'Construct a spline object from given tck and degree'

@classmethod
def _from_tck(cls, tck):

    self = cls.__new__(cls)
    if (len(tck) != 5):
        raise ValueError('tck    should    be    a    5    element    tuple    of    tx,    ty,    c,    kx,    ky')
    self.tck = tck[:3]
    self.degrees = tck[3:]
    return self
