def METHOD_NAME(self):
    """Test writing and reading of SMIRNOFF in XML format."""
    forcefield = ForceField(smirnoff99Frosst_offxml_filename)
    # Write XML to a file
    with TemporaryDirectory() as tmpdir:
        offxml_tmpfile = os.path.join(tmpdir, "forcefield.offxml")
        forcefield.save(offxml_tmpfile)
        forcefield2 = ForceField(offxml_tmpfile)
        assert_forcefields_equal(
            cls.forcefield,
            forcefield2,
            "ForceField written to .offxml does not match original ForceField",
        )