async def prefix_getter_sync_callable(prefix_factory, message):
    """
    Returns a prefix for the message.
    
    This function is a coroutine.
    
    Parameters
    ----------
    prefix_factory : `callable`
        Sync callable returning the prefix.
    message : ``Message``
        The received message to parse the prefix from.
    
    Returns
    -------
    prefix : `None`, `str`
        The respective prefix for the message. Returns `None` of non could be identified.
    """
    prefix = prefix_factory(message)
    if isinstance(prefix, str):
        pass
    elif isinstance(prefix, tuple) and (len(prefix) > 0):
        prefix = prefix[0]
    else:
        prefix = None
    
    return prefix