old_contents: #Modifies the Stage_client_stats collection of Stage_database.
  #Changes the client_ts field to ts.
  
  
  from pymongo import MongoClient
  client = MongoClient()
  db = client.Stage_database
  collection = db.Stage_client_stats
  collection.update({}, { '$rename': {"client_ts": "ts"}}, multi=True)
  
new_contents: #Modifies the Stage_client_stats collection of Stage_database.
  #Changes the client_ts field to ts.
  
  
  from pymongo import MongoClient
  client = MongoClient()
  db = client.Stage_database
  
  collection = db.Stage_client_stats
  collection.update({}, { '$rename': {"client_ts": "ts"}}, multi=True)
  
  collection = db.Stage_server_stats
  collection.update({}, { '$rename': {"client_ts": "ts"}}, multi=True)
  
  collection = db.Stage_result_stats
  collection.update({}, { '$rename': {"client_ts": "ts"}}, multi=True)
  
  
subject: update ts script