old_contents: import cerberus
  import dateutil.parser
  
  def validate_iso_datetime(field, value, error):
      try:
          dateutil.parser.parse(value)
      except ValueError:
          error(field, "invalid iso format")
  
  team_schema = {
      "name": {"type": "string", "minlength": 1, 'required': True},
      "days_of_week": {"type": "list", "schema": {'type': 'integer'}, 'required': True},
      "send_time": {"validator": validate_iso_datetime, 'required': True},
      "summary_time": {"validator": validate_iso_datetime, 'required': True},
  }
  
  user_schema = {
      "first_name": {"type": "string", "minlength": 1, 'required': True},
      "last_name": {"type": "string", "minlength": 1, 'required': True},
      'email': {'type': 'string', 'regex': '^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$', 'required': True},
      'roles': {'type': 'list', 'required': True, 'schema': {'type':'dict', 
                      'schema': {'id': {'type': ['integer', 'string'], 'required': True}, 'name': {'type': 'string', 'required': True} } } }
  }
  
  question_schema = {
      'question': {"type": "string", "minlength": 1, 'required': True},
  }
new_contents: import dateutil.parser
  
  def validate_iso_datetime(field, value, error):
      try:
          dateutil.parser.parse(value)
      except ValueError:
          error(field, "invalid iso format")
  
  team_schema = {
      "name": {"type": "string", "minlength": 1, 'required': True},
      "days_of_week": {"type": "list", "schema": {'type': 'integer'}, 'required': True},
      "send_time": {"validator": validate_iso_datetime, 'required': True},
      "summary_time": {"validator": validate_iso_datetime, 'required': True},
  }
  
  user_schema = {
      "first_name": {"type": "string", "minlength": 1, 'required': True},
      "last_name": {"type": "string", "minlength": 1, 'required': True},
      'email': {'type': 'string', 'regex': '^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$', 'required': True},
      'roles': {'type': 'list', 'required': True, 'schema': {'type':'dict', 
                      'schema': {'id': {'type': ['integer', 'string'], 'required': True}, 'name': {'type': 'string', 'required': True} } } }
  }
  
  question_schema = {
      'question': {"type": "string", "minlength": 1, 'required': True},
  }
subject: remove unused import