@property
def unit_of_measurement(self) -> (str | None):
    'Return the unit of measurement of this entity, if any.'
    if hasattr(self, '_attr_unit_of_measurement'):
        return self._attr_unit_of_measurement
    if hasattr(self, 'entity_description'):
        return self.entity_description.unit_of_measurement
    return None
Return the unit of measurement of this entity, if any.
@property
def unit_of_measurement(self) -> (str | None):
    
    if hasattr(self, '_attr_unit_of_measurement'):
        return self._attr_unit_of_measurement
    if hasattr(self, 'entity_description'):
        return self.entity_description.unit_of_measurement
    return None