How to use the tweakwcs.matchutils.MatchCatalogs function in tweakwcs

Source catalog associated with an image. Image catalog must contain
            ``'TPx'`` and ``'TPy'`` columns that provide undistorted
            (distortion-correction applied) source coordinates coordinate
            system common (shared) with the image catalog ``refcat``.

        Returns
        -------
        (refcat_idx, imcat_idx): tuple of numpy.ndarray
            A tuple of two 1D `numpy.ndarray` containing indices of matched
            sources in the ``refcat`` and ``imcat`` catalogs accordingly.

        """
        pass


class TPMatch(MatchCatalogs):
    """ Catalog source matching in tangent plane. Uses ``xyxymatch``
    algorithm to cross-match sources between this catalog and
    a reference catalog.

    .. note::
        The tangent plane is a plane tangent to the celestial sphere and it
        must be not distorted, that is, if *image* coordinates are distorted,
        then distortion correction must be applied to them before tangent
        plane coordinates are computed. Alternatively, one can think that
        undistorted world coordinates are projected from the sphere onto the
        tangent plane.

    """
    def __init__(self, searchrad=3.0, separation=0.5, use2dhist=True,
                 xoffset=0.0, yoffset=0.0, tolerance=1.0):
        """