def subscribe_many(channels):
  for channel,clients in channels.iteritems():
    for client_id in clients:
      subscribe(client_id,channel)
Return True if file already exists in the storage system.
dataset/ETHPy150Open urielka/shaveet/shaveet/api.py/subscribe_many--crossover with--dataset/ETHPy150Open benoitbryon/django-downloadview/django_downloadview/files.py/StorageFile.exists