human
Solve the following python programming problem given the following code:
@gen.coroutine
def AllocateIds(client, obj_store, user_id, device_id, request):
assistant
#Here is the Python program you requested.

    """Allocates an asset id for the current device.  The request should include the asset id prefix
    for the requested type.  Currently, only comment, activity and operation ids are supported.
    """
    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})