How to use the aexpect.utils.genio._open_log_files.pop function in aexpect

def close_log_file(filename):
    global _open_log_files, _log_file_dir, _log_lock
    remove = []
    if not _acquire_lock(_log_lock):
        raise LogLockError("Could not acquire exclusive lock to access"
                           " _open_log_files")
    try:
        for k in _open_log_files:
            if os.path.basename(k) == filename:
                f = _open_log_files[k]
                f.close()
                remove.append(k)
        if remove:
            for key_to_remove in remove:
                _open_log_files.pop(key_to_remove)
    finally:
        _log_lock.release()