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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _dy(self):
 """Return integer height of this shape's path in local units."""

        min_y = max_y = self._start_y
        for drawing_operation in self:
            if hasattr(drawing_operation, 'y'):
                min_y = min(min_y, drawing_operation.y)
                max_y = max(max_y, drawing_operation.y)
        return max_y - min_y