def METHOD_NAME(
    self,
    combined_system,
    system1,
    molecule2,
    sage,
    parsley,
):
    box = 5 * numpy.eye(3) * unit.nanometer
    parsley_system = deepcopy(system1)
    sage_system = deepcopy(system1)
    molecule2_parsley = _convert(
        Interchange.from_smirnoff(parsley, [molecule2], box=box),
    )
    molecule2_sage = _convert(Interchange.from_smirnoff(sage, [molecule2], box=box))
    parsley_system.add_molecule_type(molecule2_parsley.molecule_types["MOL2"], 1)
    sage_system.add_molecule_type(molecule2_sage.molecule_types["MOL2"], 1)
    parsley_system.positions = combined_system.positions
    sage_system.positions = combined_system.positions
    parsley_system.to_files(prefix="parsley", decimal=8)
    sage_system.to_files(prefix="sage", decimal=8)
    get_intermol_defaults(periodic=True).write_mdp_file("tmp.mdp")
    _parsley_energy = _process(
        _run_gmx_energy("parsley.top", "parsley.gro", "tmp.mdp"),
    )
    _sage_energy = _process(_run_gmx_energy("sage.top", "sage.gro", "tmp.mdp"))
    assert _parsley_energy != _sage_energy