def line(self, x1, y1, x2, y2, draw=True):
p = self._path<EOL>self.beginpath()<EOL>self.moveto(x1, y1)<EOL>self.lineto(x2, y2)<EOL>self.endpath(draw=draw)<EOL>self._path = p<EOL>return p<EOL>
Draw a line from (x1,y1) to (x2,y2)
        :param x1: start x-coordinate
        :param y1: start y-coordinate
        :param x2: end x-coordinate
        :param y2: end y-coordinate