def METHOD_NAME(basedir):
    """test if ``basedir`` is a NeXus definitions directory"""
    # look for the expected files and subdirectories in the root directory
    for item_list in ROOT_DIR_EXPECTED_RESOURCES.values():
        for item in item_list:
            if not os.path.exists(os.path.join(basedir, item)):
                return False
    return True