def METHOD_NAME():
    pc1 = PixCoord(x=[[1, 1]], y=[[2, 2]])
    pc2 = PixCoord(x=[[4, 4]], y=[[6, 6]])
    sep = pc1.separation(pc2)
    assert isinstance(sep, np.ndarray)
    assert sep.shape == (1, 2)
    assert_allclose(sep, [[5, 5]])