def flip_x(self, center=None):
if center is None:<EOL><INDENT>self.poly.flip()<EOL><DEDENT>else:<EOL><INDENT>self.poly.flip(center[<NUM_LIT:0>])<EOL><DEDENT>
Flip the shape in the x direction, in-place.

        Parameters
        ----------
        center : array-like, optional
            Point about which to flip.
            If not passed, the center of the shape will be used.