def METHOD_NAME(xy1, xy2, xy3, xy4):
    """
        Returns the intersection of two lines.
    """
    (x1, y1) = xy1
    (x2, y2) = xy2
    (x3, y3) = xy3
    (x4, y4) = xy4
    b = (x2 - x1, y2 - y1)
    d = (x4 - x3, y4 - y3)
    det = b[0] * d[1] - b[1] * d[0]
    if det == 0:
        return None
    c = (x3 - x1, y3 - y1)
    t = float(c[0] * b[1] - c[1] * b[0]) / (det * 1.0)
    if t < 0.0 or t > 1.0:
        return None
    t = float(c[0] * d[1] - c[1] * d[0]) / (det * 1.0)
    if t < 0.0 or t > 1.0:
        return None
    x = x1 + t * b[0]
    y = y1 + t * b[1]
    return (x, y)