human
I wrote the below code

    prefixes = request['asset_types']
    timestamp = util.GetCurrentTimestamp()
    def ValidateId(prefix):
        'Validate    a    single    requested    Id'
        if (not IdPrefix.IsValid(prefix)):
            raise InvalidRequestError(UNSUPPORTED_ASSET_TYPE, asset_type=prefix)
        if (not (prefix in 'acop')):
            raise InvalidRequestError(UNSUPPORTED_ASSET_TYPE, asset_type=IdPrefix.GetAssetName(prefix))
    def ConstructId(prefix, uniquifier):
        if (prefix == 'a'):
            asset_id = Activity.ConstructActivityId(timestamp, device_id, uniquifier)
        elif (prefix == 'c'):
            asset_id = Comment.ConstructCommentId(timestamp, device_id, uniquifier)
        elif (prefix == 'p'):
            asset_id = Photo.ConstructPhotoId(timestamp, device_id, uniquifier)
        else:
            asset_id = Operation.ConstructOperationId(device_id, uniquifier)
        return asset_id
    for prefix in prefixes:
        ValidateId(prefix)
    unique_start = (yield gen.Task(User.AllocateAssetIds, client, user_id, len(prefixes)))
    asset_ids = [ConstructId(p, u) for (p, u) in zip(prefixes, range(unique_start, (unique_start + len(prefixes))))]
    raise gen.Return({'asset_ids': asset_ids, 'timestamp': timestamp})

What's a good function header?
 ... Give me a Python program to fix in 'acop')):?
assistant
#Here is Python program to fix in 'acop')):
.

@gen.coroutine
def AllocateIds(client, obj_store, user_id, device_id, request):