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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def classify_coincident(st_vals, coincident):
 r"""Determine if coincident parameters are "unused". .. note:: This is a helper for :func:`surface_intersections`. In the case that ``coincident`` is :data:`True`, then we'll have two sets of parameters :math:`(s_1, t_1)` and :math:`(s_2, t_2)`. If one of :math:`s1 < s2` or :math:`t1 < t2` is not satisfied, the coincident segments will be moving in opposite directions, hence don't define an interior of an intersection. .. warning:: In the "coincident" case, this assumes, but doesn't check, that ``st_vals`` is ``2 x 2``. Args: st_vals (numpy.ndarray):
 ``2 X N`` array of intersection parameters. coincident (bool):
 Flag indicating if the intersections are the endpoints of coincident segments of two curves. Returns: Optional[.IntersectionClassification]: The classification of the intersections. """

    if not coincident:
        return None

    if st_vals[0, 0] >= st_vals[0, 1] or st_vals[1, 0] >= st_vals[1, 1]:
        return UNUSED_T

    else:
        return CLASSIFICATION_T.COINCIDENT