def METHOD_NAME(u, sels, density, value):
    kwargs = {'density': density} if density is not None else {}
    rdf = InterRDF_s(u, sels, **kwargs).run()
    assert_almost_equal(max(rdf.results.rdf[0][0][0]), value)
    if not density:
        s1 = u.select_atoms('name ZND and resid 289')
        s2 = u.select_atoms(
                'name OD1 and resid 51 and sphzone 5.0 (resid 289)')
        rdf_ref = InterRDF(s1, s2).run()
        assert_almost_equal(rdf_ref.results.rdf, rdf.results.rdf[0][0][0])