Make min and max functions public

Author: matthias-wende-frequenz

src/frequenz/sdk/timeseries/_formula_engine/_formula_engine.py

@@ -172,7 +172,7 @@ def __truediv__(
         """
         return self._higher_order_builder(self, self._create_method) / other  # type: ignore
 
-    def _max(
+    def max(
         self, other: _GenericEngine | _GenericHigherOrderBuilder | QuantityT
     ) -> _GenericHigherOrderBuilder:
         """Return a formula engine that outputs the maximum of `self` and `other`.
@@ -187,7 +187,7 @@ def _max(
         """
         return self._higher_order_builder(self, self._create_method).max(other)  # type: ignore
 
-    def _min(
+    def min(
         self, other: _GenericEngine | _GenericHigherOrderBuilder | QuantityT
     ) -> _GenericHigherOrderBuilder:
         """Return a formula engine that outputs the minimum of `self` and `other`.

tests/timeseries/_formula_engine/test_formula_composition.py

@@ -176,11 +176,11 @@ async def test_formula_composition_min_max(self, mocker: MockerFixture) -> None:
         await mockgrid.start(mocker)
 
         logical_meter = microgrid.logical_meter()
-        engine_min = logical_meter.grid_power._min(  # pylint: disable=protected-access
+        engine_min = logical_meter.grid_power.min(  # pylint: disable=protected-access
             Power.zero()
         ).build("grid_power_min")
         engine_min_rx = engine_min.new_receiver()
-        engine_max = logical_meter.grid_power._max(  # pylint: disable=protected-access
+        engine_max = logical_meter.grid_power.max(  # pylint: disable=protected-access
             Power.zero()
         ).build("grid_power_max")
         engine_max_rx = engine_max.new_receiver()