Address review remarks

Author: matemaciek

adafruit_display_shapes/multisparkline.py

@@ -141,7 +141,7 @@ def __init__(
         # y_bottom: The actual minimum value of the vertical scale, will be
         # updated if autorange
         self.y_tops = self.y_maxs.copy()
-        # y_top: The actual minimum value of the vertical scale, will be
+        # y_top: The actual maximum value of the vertical scale, will be
         # updated if autorange
         self._palette = displayio.Palette(self._lines + 1)
         self._palette.make_transparent(0)
@@ -194,7 +194,7 @@ def add_values(self, values: List[float], update: bool = True) -> None:
                 self.y_bottoms[i] = bottom
 
                 if update:
-                    self.update(i)
+                    self.update_line(i)
 
     @staticmethod
     def _xintercept(

adafruit_display_shapes/sparkline.py

@@ -104,3 +104,17 @@ def values(self) -> List[float]:
         """Returns the values displayed on the sparkline."""
 
         return self.values_of(0)
+
+    @property
+    def y_top(self) -> float:
+        """
+        :return: The actual maximum value of the vertical scale, will be updated if autorange
+        """
+        return self.y_tops[0]
+
+    @property
+    def y_bottom(self) -> float:
+        """
+        :return: The actual minimum value of the vertical scale, will be updated if autorange
+        """
+        return self.y_bottoms[0]