human
I wrote the below code

    def maybe_call_method(instance, is_raw, method_name):
        'Call    an    (un-)indexing    method    on    instance    if    appropriate.'
        obj = instance_to_indexee(instance)
        if ((obj is not None) and (not is_raw)):
            getattr(obj, method_name)()
    def update(sender, instance, **kw):
        'File    an    add-to-index    task    for    the    indicated    object.'
        maybe_call_method(instance, kw.get('raw'), 'index_later')
    def delete(sender, instance, **kw):
        'File    a    remove-from-index    task    for    the    indicated    object.'
        maybe_call_method(instance, kw.get('raw'), 'unindex_later')
    def indexing_receiver(signal, signal_name):
        'Return    a    routine    that    registers    signal    handlers    for    indexers.\n\n                                The    returned    registration    routine    uses    strong    refs,    makes    up    a\n                                dispatch_uid,    and    uses    ``sender_class``    as    the    sender.\n\n                                '
        return receiver(signal, sender=sender_class, dispatch_uid=('%s.%s.elastic.%s' % (app, sender_class.__name__, signal_name)), weak=False)
    if m2m:
        indexing_receiver(m2m_changed, 'm2m_changed')(update)
    else:
        indexing_receiver(post_save, 'post_save')(update)
        indexing_receiver(pre_delete, 'pre_delete')((delete if (instance_to_indexee is _identity) else update))

What's a good function header?
assistant
#Here's a good function header.

def register_for_indexing(app, sender_class, instance_to_indexee=_identity, m2m=False):