Retrieves the the bottom left coordinate of the line as tuple.
        Coordinates must be numbers.

def getBottomLeft(self):
        """
        Retrieves the the bottom left coordinate of the line as tuple.
        Coordinates must be numbers.
        """
        x1 = float(self.get_x1())
        x2 = float(self.get_x2())
        y1 = float(self.get_y1())
        y2 = float(self.get_y2())
        if x1 < x2:
            if y1 < y2:
                return (x1, y1)
            else:
                return (x1, y2)
        else:
            if y1 < y2:
                return (x2, y1)
            else:
                return (x2, y2)