def METHOD_NAME(self, other):
    """ Returns the envelope of two :class:`Rect`, i.e., a smallest
        rectange contaning the input rectangles.
    """
    return Rect(
        offset_x=min(self.offset_x, other[0]),
        offset_y=min(self.offset_y, other[1]),
        upper_x=max(self.upper_x, other[0] + other[2]),
        upper_y=max(self.upper_y, other[1] + other[3])
    )