def __call__(coords):
    """Find matching points.

        Parameters
        ----------
        B : array_like(Number, shape=(n, k))
            Represents `n` points of `k` dimensions. These points are assigned
            to the previously defined reference coordinates.

        Returns
        -------
        pairs : np.ndarray(int, shape=(m, 2))
            Indices of assigned points. For two point sets `A`, `B` and each
            row `(a, b)` in `pairs` `A[a, :]` is assigned to `B[b, :]`

        """
    raise NotImplementedError()
