def initialize_namespace(self, app_id, namespace):
    if app_id not in self.namespace_info:
      self.namespace_info[app_id] = {namespace: {'size': 0, 'number': 0}}

    if namespace not in self.namespace_info[app_id]:
      self.namespace_info[app_id] = {namespace: {'size': 0, 'number': 0}}
    if namespace not in self.namespace_info[app_id]:
      self.stats[app_id][namespace] = {'size': 0, 'number': 0}
Puts a namespace into the namespace object if
dataset/ETHPy150Open AppScale/appscale/AppDB/groomer.py/DatastoreGroomer.initialize_namespace