def METHOD_NAME(cls):
    cls.es_list = list()
    file_list = ["vasprun_1.xml", "vasprun_2.xml"]
    for f in file_list:
        vp = Vasprun()
        direc = os.path.abspath(
            os.path.join(
                os.path.dirname(os.path.abspath(__file__)),
                "../../static/vasp_test_files/vasprun_samples",
            )
        )
        filename = posixpath.join(direc, f)
        vp.from_file(filename)
        es = vp.get_electronic_structure()
        cls.es_list.append(es)