def toggle(self, x, y):
x = normalize(x)<EOL>y = normalize(y)<EOL>col, row = get_pos(x, y)<EOL>if type(self.chars[row][col]) != int or self.chars[row][col] & pixel_map[y % <NUM_LIT:4>][x % <NUM_LIT:2>]:<EOL><INDENT>self.unset(x, y)<EOL><DEDENT>else:<EOL><INDENT>self.set(x, y)<EOL><DEDENT>
Toggle a pixel of the :class:`Canvas` object.

        :param x: x coordinate of the pixel
        :param y: y coordinate of the pixel