diff --git a/src/data_morph/bounds/bounding_box.py b/src/data_morph/bounds/bounding_box.py
index 1fe77437..8aa4d8c2 100644
--- a/src/data_morph/bounds/bounding_box.py
+++ b/src/data_morph/bounds/bounding_box.py
@@ -170,25 +170,25 @@ def clone(self) -> BoundingBox:
         )
 
     @property
-    def range(self) -> Iterable[Number]:
+    def range(self) -> tuple[Number, Number]:
         """
         Calculate the range (width) of the bounding box in each direction.
 
         Returns
         -------
-        Iterable[numbers.Number]
+        tuple[Number, Number]
             The range covered by the x and y bounds, respectively.
         """
         return self.x_bounds.range, self.y_bounds.range
 
     @property
-    def center(self) -> Iterable[Number]:
+    def center(self) -> tuple[Number, Number]:
         """
         Calculate the center of the bounding box.
 
         Returns
         -------
-        Iterable[numbers.Number]
+        tuple[Number, Number]
             The center of the x and y bounds, respectively.
         """
         return self.x_bounds.center, self.y_bounds.center
diff --git a/src/data_morph/shapes/circles.py b/src/data_morph/shapes/circles.py
deleted file mode 100644
index c251da1c..00000000
--- a/src/data_morph/shapes/circles.py
+++ /dev/null
@@ -1,213 +0,0 @@
-"""Shapes that are circular in nature."""
-
-from __future__ import annotations
-
-from typing import TYPE_CHECKING
-
-import matplotlib.pyplot as plt
-import numpy as np
-
-from ..plotting.style import plot_with_custom_style
-from .bases.shape import Shape
-
-if TYPE_CHECKING:
-    from numbers import Number
-
-    from matplotlib.axes import Axes
-
-    from ..data.dataset import Dataset
-
-
-class Circle(Shape):
-    """
-    Class representing a hollow circle.
-
-    .. plot::
-       :scale: 75
-       :caption:
-            This shape is generated using the panda dataset.
-
-        from data_morph.data.loader import DataLoader
-        from data_morph.shapes.circles import Circle
-
-        _ = Circle(DataLoader.load_dataset('panda')).plot()
-
-    Parameters
-    ----------
-    dataset : Dataset
-        The starting dataset to morph into other shapes.
-    radius : numbers.Number, optional
-        The radius of the circle.
-    """
-
-    def __init__(self, dataset: Dataset, radius: Number | None = None) -> None:
-        self.center: np.ndarray = dataset.data[['x', 'y']].mean().to_numpy()
-        """numpy.ndarray: The (x, y) coordinates of the circle's center."""
-
-        self.radius: Number = radius or dataset.data[['x', 'y']].std().mean() * 1.5
-        """numbers.Number: The radius of the circle."""
-
-    def __repr__(self) -> str:
-        x, y = self.center
-        return f'<{self.__class__.__name__} center={(float(x), float(y))} radius={self.radius}>'
-
-    def distance(self, x: Number, y: Number) -> float:
-        """
-        Calculate the absolute distance between this circle's edge and a point (x, y).
-
-        Parameters
-        ----------
-        x, y : numbers.Number
-            Coordinates of a point in 2D space.
-
-        Returns
-        -------
-        float
-            The absolute distance between this circle's edge and the point (x, y).
-        """
-        return abs(
-            self._euclidean_distance(self.center, np.array([x, y])) - self.radius
-        )
-
-    @plot_with_custom_style
-    def plot(self, ax: Axes | None = None) -> Axes:
-        """
-        Plot the shape.
-
-        Parameters
-        ----------
-        ax : matplotlib.axes.Axes, optional
-            An optional :class:`~matplotlib.axes.Axes` object to plot on.
-
-        Returns
-        -------
-        matplotlib.axes.Axes
-            The :class:`~matplotlib.axes.Axes` object containing the plot.
-        """
-        if not ax:
-            fig, ax = plt.subplots(layout='constrained')
-            fig.get_layout_engine().set(w_pad=0.2, h_pad=0.2)
-        _ = ax.axis('equal')
-        _ = ax.add_patch(plt.Circle(self.center, self.radius, ec='k', fill=False))
-        _ = ax.autoscale()
-        return ax
-
-
-class Rings(Shape):
-    """
-    Class representing rings comprising multiple concentric circles.
-
-    .. plot::
-       :scale: 75
-       :caption:
-            This shape is generated using the panda dataset.
-
-        from data_morph.data.loader import DataLoader
-        from data_morph.shapes.circles import Rings
-
-        _ = Rings(DataLoader.load_dataset('panda')).plot()
-
-    Parameters
-    ----------
-    dataset : Dataset
-        The starting dataset to morph into other shapes.
-    num_rings : int, default ``4``
-        The number of rings to include. Must be greater than 1.
-
-    See Also
-    --------
-    Circle : The individual rings are represented as circles.
-    """
-
-    def __init__(self, dataset: Dataset, num_rings: int = 4) -> None:
-        if not isinstance(num_rings, int):
-            raise TypeError('num_rings must be an integer')
-        if num_rings <= 1:
-            raise ValueError('num_rings must be greater than 1')
-
-        stdev = dataset.data.std().mean()
-        self.circles: list[Circle] = [
-            Circle(dataset, r)
-            for r in np.linspace(stdev / num_rings * 2, stdev * 2, num_rings)
-        ]
-        """list[Circle]: The individual rings represented by :class:`Circle` objects."""
-
-        self._centers = np.array([circle.center for circle in self.circles])
-        self._radii = np.array([circle.radius for circle in self.circles])
-
-    def __repr__(self) -> str:
-        return self._recursive_repr('circles')
-
-    def distance(self, x: Number, y: Number) -> float:
-        """
-        Calculate the minimum absolute distance between any of this shape's
-        circles' edges and a point (x, y).
-
-        Parameters
-        ----------
-        x, y : numbers.Number
-            Coordinates of a point in 2D space.
-
-        Returns
-        -------
-        float
-            The minimum absolute distance between any of this shape's
-            circles' edges and the point (x, y).
-
-        See Also
-        --------
-        Circle.distance :
-            Rings consists of multiple circles, so we use the minimum
-            distance to one of the circles.
-        """
-        point = np.array([x, y])
-        return np.min(
-            np.abs(np.linalg.norm(self._centers - point, axis=1) - self._radii)
-        )
-
-    @plot_with_custom_style
-    def plot(self, ax: Axes | None = None) -> Axes:
-        """
-        Plot the shape.
-
-        Parameters
-        ----------
-        ax : matplotlib.axes.Axes, optional
-            An optional :class:`~matplotlib.axes.Axes` object to plot on.
-
-        Returns
-        -------
-        matplotlib.axes.Axes
-            The :class:`~matplotlib.axes.Axes` object containing the plot.
-        """
-        for circle in self.circles:
-            ax = circle.plot(ax)
-        return ax
-
-
-class Bullseye(Rings):
-    """
-    Class representing a bullseye shape comprising two concentric circles.
-
-    .. plot::
-       :scale: 75
-       :caption:
-            This shape is generated using the panda dataset.
-
-        from data_morph.data.loader import DataLoader
-        from data_morph.shapes.circles import Bullseye
-
-        _ = Bullseye(DataLoader.load_dataset('panda')).plot()
-
-    Parameters
-    ----------
-    dataset : Dataset
-        The starting dataset to morph into other shapes.
-
-    See Also
-    --------
-    Rings : The Bullseye is a special case where we only have 2 rings.
-    """
-
-    def __init__(self, dataset: Dataset) -> None:
-        super().__init__(dataset=dataset, num_rings=2)
diff --git a/src/data_morph/shapes/circles/__init__.py b/src/data_morph/shapes/circles/__init__.py
new file mode 100644
index 00000000..7468cd8c
--- /dev/null
+++ b/src/data_morph/shapes/circles/__init__.py
@@ -0,0 +1,11 @@
+"""Shapes made up of circles."""
+
+from .bullseye import Bullseye
+from .circle import Circle
+from .rings import Rings
+
+__all__ = [
+    'Bullseye',
+    'Circle',
+    'Rings',
+]
diff --git a/src/data_morph/shapes/circles/bullseye.py b/src/data_morph/shapes/circles/bullseye.py
new file mode 100644
index 00000000..b4fd6d09
--- /dev/null
+++ b/src/data_morph/shapes/circles/bullseye.py
@@ -0,0 +1,50 @@
+"""Bullseye shape."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import numpy as np
+
+from .rings import Rings
+
+if TYPE_CHECKING:
+    from ..data.dataset import Dataset
+
+
+class Bullseye(Rings):
+    """
+    Class representing a bullseye shape comprising two concentric circles.
+
+    .. plot::
+       :scale: 75
+       :caption:
+            This shape is generated using the panda dataset.
+
+        from data_morph.data.loader import DataLoader
+        from data_morph.shapes.circles import Bullseye
+
+        _ = Bullseye(DataLoader.load_dataset('panda')).plot()
+
+    See Also
+    --------
+    Circle : The individual rings are represented as circles.
+    """
+
+    @staticmethod
+    def _derive_radii(dataset: Dataset) -> np.ndarray:
+        """
+        Derive the radii for the circles in the bullseye.
+
+        Parameters
+        ----------
+        dataset : Dataset
+            The starting dataset to morph into.
+
+        Returns
+        -------
+        np.ndarray
+            The radii for the circles in the bullseye.
+        """
+        stdev = dataset.data[['x', 'y']].std().mean() * 1.5
+        return np.linspace(stdev, 0, 2, endpoint=False)
diff --git a/src/data_morph/shapes/circles/circle.py b/src/data_morph/shapes/circles/circle.py
new file mode 100644
index 00000000..1aee9e2a
--- /dev/null
+++ b/src/data_morph/shapes/circles/circle.py
@@ -0,0 +1,93 @@
+"""Circle shape."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+from ...plotting.style import plot_with_custom_style
+from ..bases.shape import Shape
+
+if TYPE_CHECKING:
+    from numbers import Number
+
+    from matplotlib.axes import Axes
+
+    from ..data.dataset import Dataset
+
+
+class Circle(Shape):
+    """
+    Class representing a hollow circle.
+
+    .. plot::
+       :scale: 75
+       :caption:
+            This shape is generated using the panda dataset.
+
+        from data_morph.data.loader import DataLoader
+        from data_morph.shapes.circles import Circle
+
+        _ = Circle(DataLoader.load_dataset('panda')).plot()
+
+    Parameters
+    ----------
+    dataset : Dataset
+        The starting dataset to morph into other shapes.
+    radius : numbers.Number, optional
+        The radius of the circle.
+    """
+
+    def __init__(self, dataset: Dataset, radius: Number | None = None) -> None:
+        self.center: tuple[Number, Number] = dataset.data_bounds.center
+        """The (x, y) coordinates of the circle's center."""
+
+        self.radius: Number = radius or dataset.data[['x', 'y']].std().mean() * 1.5
+        """The radius of the circle."""
+
+    def __repr__(self) -> str:
+        x, y = self.center
+        return f'<{self.__class__.__name__} center={(float(x), float(y))} radius={self.radius}>'
+
+    def distance(self, x: Number, y: Number) -> float:
+        """
+        Calculate the absolute distance between this circle's edge and a point (x, y).
+
+        Parameters
+        ----------
+        x, y : numbers.Number
+            Coordinates of a point in 2D space.
+
+        Returns
+        -------
+        float
+            The absolute distance between this circle's edge and the point (x, y).
+        """
+        return abs(
+            self._euclidean_distance(self.center, np.array([x, y])) - self.radius
+        )
+
+    @plot_with_custom_style
+    def plot(self, ax: Axes | None = None) -> Axes:
+        """
+        Plot the shape.
+
+        Parameters
+        ----------
+        ax : matplotlib.axes.Axes, optional
+            An optional :class:`~matplotlib.axes.Axes` object to plot on.
+
+        Returns
+        -------
+        matplotlib.axes.Axes
+            The :class:`~matplotlib.axes.Axes` object containing the plot.
+        """
+        if not ax:
+            fig, ax = plt.subplots(layout='constrained')
+            fig.get_layout_engine().set(w_pad=0.2, h_pad=0.2)
+        _ = ax.axis('equal')
+        _ = ax.add_patch(plt.Circle(self.center, self.radius, ec='k', fill=False))
+        _ = ax.autoscale()
+        return ax
diff --git a/src/data_morph/shapes/circles/rings.py b/src/data_morph/shapes/circles/rings.py
new file mode 100644
index 00000000..bf571c20
--- /dev/null
+++ b/src/data_morph/shapes/circles/rings.py
@@ -0,0 +1,113 @@
+"""Rings shape."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import numpy as np
+
+from ...plotting.style import plot_with_custom_style
+from ..bases.shape import Shape
+from .circle import Circle
+
+if TYPE_CHECKING:
+    from numbers import Number
+
+    from matplotlib.axes import Axes
+
+    from ..data.dataset import Dataset
+
+
+class Rings(Shape):
+    """
+    Class representing rings comprising three concentric circles.
+
+    .. plot::
+       :scale: 75
+       :caption:
+            This shape is generated using the panda dataset.
+
+        from data_morph.data.loader import DataLoader
+        from data_morph.shapes.circles import Rings
+
+        _ = Rings(DataLoader.load_dataset('panda')).plot()
+
+    Parameters
+    ----------
+    dataset : Dataset
+        The starting dataset to morph into other shapes.
+
+    See Also
+    --------
+    Circle : The individual rings are represented as circles.
+    """
+
+    def __init__(self, dataset: Dataset) -> None:
+        self.circles: list[Circle] = [
+            Circle(dataset, radius) for radius in self._derive_radii(dataset)
+        ]
+        """The individual rings represented by :class:`Circle` objects."""
+
+        self._centers = np.array([circle.center for circle in self.circles])
+        self._radii = np.array([circle.radius for circle in self.circles])
+
+    def __repr__(self) -> str:
+        return self._recursive_repr('circles')
+
+    @staticmethod
+    def _derive_radii(dataset: Dataset) -> np.ndarray:
+        """
+        Derive the radii for the circles in the rings.
+
+        Parameters
+        ----------
+        dataset : Dataset
+            The starting dataset to morph into.
+
+        Returns
+        -------
+        np.ndarray
+            The radii for the circles in the rings.
+        """
+        stdev = (min(dataset.data_bounds.range) + min(dataset.morph_bounds.range)) / 4
+        return np.linspace(stdev, 0, 3, endpoint=False)
+
+    def distance(self, x: Number, y: Number) -> float:
+        """
+        Calculate the minimum absolute distance between any of this shape's
+        circles' edges and a point (x, y).
+
+        Parameters
+        ----------
+        x, y : numbers.Number
+            Coordinates of a point in 2D space.
+
+        Returns
+        -------
+        float
+            The minimum absolute distance between any of this shape's
+            circles' edges and the point (x, y).
+        """
+        point = np.array([x, y])
+        return np.min(
+            np.abs(np.linalg.norm(self._centers - point, axis=1) - self._radii)
+        )
+
+    @plot_with_custom_style
+    def plot(self, ax: Axes | None = None) -> Axes:
+        """
+        Plot the shape.
+
+        Parameters
+        ----------
+        ax : matplotlib.axes.Axes, optional
+            An optional :class:`~matplotlib.axes.Axes` object to plot on.
+
+        Returns
+        -------
+        matplotlib.axes.Axes
+            The :class:`~matplotlib.axes.Axes` object containing the plot.
+        """
+        for circle in self.circles:
+            ax = circle.plot(ax)
+        return ax
diff --git a/tests/shapes/circles/bases.py b/tests/shapes/circles/bases.py
index ca1912af..ae8210fd 100644
--- a/tests/shapes/circles/bases.py
+++ b/tests/shapes/circles/bases.py
@@ -5,8 +5,12 @@
 import re
 from typing import TYPE_CHECKING
 
+import matplotlib.pyplot as plt
+import numpy as np
 import pytest
 
+from data_morph.shapes.circles import Circle
+
 if TYPE_CHECKING:
     from numbers import Number
 
@@ -30,8 +34,38 @@ def test_distance(self, shape, test_point, expected_distance):
         Test the distance() method parametrized by distance_test_cases
         (see conftest.py).
         """
-        assert pytest.approx(shape.distance(*test_point)) == expected_distance
+        actual_distance = shape.distance(*test_point)
+        assert pytest.approx(actual_distance) == expected_distance
 
     def test_repr(self, shape):
         """Test that the __repr__() method is working."""
         assert re.match(self.repr_regex, repr(shape)) is not None
+
+    @pytest.mark.parametrize('ax', [None, plt.subplots()[1]])
+    def test_plot(self, shape, ax):
+        """Test that the plot() method is working."""
+        if ax:
+            ax.clear()
+
+        plot_ax = shape.plot(ax)
+        if ax:
+            assert plot_ax is ax
+        else:
+            assert plot_ax is not ax
+
+        plotted_circles = plot_ax.patches
+        plotted_centers = {plotted_circle._center for plotted_circle in plotted_circles}
+        plotted_radii = {
+            plotted_circle._width / 2 for plotted_circle in plotted_circles
+        }
+
+        if isinstance(shape, Circle):
+            assert len(plotted_circles) == 1
+            assert plotted_centers == {shape.center}
+            assert plotted_radii == {shape.radius}
+        else:
+            assert len(plotted_circles) == len(shape.circles)
+            assert plotted_centers == {tuple(np.unique(shape._centers))}
+            assert plotted_radii.difference(shape._radii) == set()
+
+        plt.close()
diff --git a/tests/shapes/circles/test_bullseye.py b/tests/shapes/circles/test_bullseye.py
index 3bd0d239..0b5053de 100644
--- a/tests/shapes/circles/test_bullseye.py
+++ b/tests/shapes/circles/test_bullseye.py
@@ -12,7 +12,44 @@ class TestBullseye(CirclesModuleTestBase):
     """Test the Bullseye class."""
 
     shape_name = 'bullseye'
-    distance_test_cases = (((20, 50), 3.660254), ((10, 25), 9.08004))
+    center_x, center_y = (20, 65)
+    inner_radius, outer_radius = (10.24519052838329, 20.49038105676658)
+    mid_radius = (outer_radius + inner_radius) / 2
+    distance_test_cases = (
+        ((center_x, center_y + outer_radius), 0),  # north on outer ring
+        ((center_x, center_y + inner_radius), 0),  # north on inner ring
+        ((center_x, center_y - outer_radius), 0),  # south on outer ring
+        ((center_x, center_y - inner_radius), 0),  # south on inner ring
+        ((center_x + outer_radius, center_y), 0),  # east on outer ring
+        ((center_x + inner_radius, center_y), 0),  # east on inner ring
+        ((center_x - outer_radius, center_y), 0),  # west on outer ring
+        ((center_x - inner_radius, center_y), 0),  # west on inner ring
+        ((center_x, center_y), inner_radius),  # center of bullseye
+        (
+            (center_x, center_y + mid_radius),
+            inner_radius / 2,
+        ),  # between the circles (north)
+        (
+            (center_x, center_y - mid_radius),
+            inner_radius / 2,
+        ),  # between the circles (south)
+        (
+            (center_x + mid_radius, center_y),
+            inner_radius / 2,
+        ),  # between the circles (east)
+        (
+            (center_x - mid_radius, center_y),
+            inner_radius / 2,
+        ),  # between the circles (west)
+        (
+            (center_x, center_y + outer_radius * 2),
+            outer_radius,
+        ),  # north of both circles
+        (
+            (center_x - outer_radius * 1.5, center_y),
+            inner_radius,
+        ),  # west of both circles
+    )
     repr_regex = (
         r'^<Bullseye>\n'
         r'  circles=\n'
diff --git a/tests/shapes/circles/test_circle.py b/tests/shapes/circles/test_circle.py
index 7e1372a8..2daa251d 100644
--- a/tests/shapes/circles/test_circle.py
+++ b/tests/shapes/circles/test_circle.py
@@ -12,7 +12,17 @@ class TestCircle(CirclesModuleTestBase):
     """Test the Circle class."""
 
     shape_name = 'circle'
-    distance_test_cases = (((20, 50), 10.490381), ((10, 25), 15.910168))
+    center_x, center_y = (20, 65)
+    radius = 20.49038105676658
+    distance_test_cases = (
+        ((center_x, center_y + radius), 0),  # north
+        ((center_x, center_y - radius), 0),  # south
+        ((center_x + radius, center_y), 0),  # east
+        ((center_x - radius, center_y), 0),  # west
+        ((center_x, center_y), radius),  # center of circle
+        ((10, 25), 20.740675199410028),  # inside the circle
+        ((-20, 0), 55.831306555602154),  # outside the circle
+    )
     repr_regex = '^' + CIRCLE_REPR + '$'
 
     def test_is_circle(self, shape):
diff --git a/tests/shapes/circles/test_rings.py b/tests/shapes/circles/test_rings.py
index 5ef0776c..502a9901 100644
--- a/tests/shapes/circles/test_rings.py
+++ b/tests/shapes/circles/test_rings.py
@@ -12,34 +12,74 @@ class TestRings(CirclesModuleTestBase):
     """Test the Rings class."""
 
     shape_name = 'rings'
-    distance_test_cases = (((20, 50), 3.16987), ((10, 25), 9.08004))
+    center_x, center_y = (20, 65)
+    radii = (3.666666666666667, 7.333333333333334, 11)
+    mid_radii = (sum(radii[:2]) / 2, sum(radii[1:]) / 2)
+    distance_test_cases = (
+        ((center_x, center_y + radii[0]), 0),  # north on inner ring
+        ((center_x, center_y + radii[1]), 0),  # north on middle ring
+        ((center_x, center_y + radii[2]), 0),  # north on outer ring
+        ((center_x, center_y - radii[0]), 0),  # south on inner ring
+        ((center_x, center_y - radii[1]), 0),  # south on middle ring
+        ((center_x, center_y - radii[2]), 0),  # south on outer ring
+        ((center_x + radii[0], center_y), 0),  # east on inner ring
+        ((center_x + radii[1], center_y), 0),  # east on middle ring
+        ((center_x + radii[2], center_y), 0),  # east on outer ring
+        ((center_x - radii[0], center_y), 0),  # west on inner ring
+        ((center_x - radii[1], center_y), 0),  # west on middle ring
+        ((center_x - radii[2], center_y), 0),  # west on outer ring
+        ((center_x, center_y), radii[0]),  # center of all rings
+        (
+            (center_x, center_y + mid_radii[0]),
+            radii[0] / 2,
+        ),  # between the inner circles (north)
+        (
+            (center_x, center_y - mid_radii[0]),
+            radii[0] / 2,
+        ),  # between the inner circles (south)
+        (
+            (center_x + mid_radii[0], center_y),
+            radii[0] / 2,
+        ),  # between the inner circles (east)
+        (
+            (center_x - mid_radii[0], center_y),
+            radii[0] / 2,
+        ),  # between the inner circles (west)
+        (
+            (center_x, center_y + mid_radii[1]),
+            radii[0] / 2,
+        ),  # between the outer circles (north)
+        (
+            (center_x, center_y - mid_radii[1]),
+            radii[0] / 2,
+        ),  # between the outer circles (south)
+        (
+            (center_x + mid_radii[1], center_y),
+            radii[0] / 2,
+        ),  # between the outer circles (east)
+        (
+            (center_x - mid_radii[1], center_y),
+            radii[0] / 2,
+        ),  # between the outer circles (west)
+        ((center_x, center_y + radii[2] * 2), radii[2]),  # north of all circles
+        ((center_x - radii[2] * 1.5, center_y), radii[2] / 2),  # west of all circles
+    )
     repr_regex = (
         r'^<Rings>\n'
         r'  circles=\n'
         r'          ' + CIRCLE_REPR + '\n'
         r'          ' + CIRCLE_REPR + '\n'
-        r'          ' + CIRCLE_REPR + '\n'
         r'          ' + CIRCLE_REPR + '$'
     )
 
-    @pytest.mark.parametrize('num_rings', [3, 5])
-    def test_init(self, shape_factory, num_rings):
-        """Test that the Rings contains multiple concentric circles."""
-        shape = shape_factory.generate_shape(self.shape_name, num_rings=num_rings)
+    def test_init(self, shape_factory):
+        """Test that the Rings contains three concentric circles."""
+        shape = shape_factory.generate_shape(self.shape_name)
 
+        num_rings = 3
         assert len(shape.circles) == num_rings
         assert all(
             np.array_equal(circle.center, shape.circles[0].center)
             for circle in shape.circles[1:]
         )
         assert len({circle.radius for circle in shape.circles}) == num_rings
-
-    @pytest.mark.parametrize('num_rings', ['3', -5, 1, True])
-    def test_num_rings_is_valid(self, shape_factory, num_rings):
-        """Test that num_rings input validation is working."""
-        if isinstance(num_rings, int):
-            with pytest.raises(ValueError, match='num_rings must be greater than 1'):
-                _ = shape_factory.generate_shape(self.shape_name, num_rings=num_rings)
-        else:
-            with pytest.raises(TypeError, match='num_rings must be an integer'):
-                _ = shape_factory.generate_shape(self.shape_name, num_rings=num_rings)