code: def serialize_to_string(self, name, datas):
          
          value = datas.get('value', None)
  
          if value is None:
              msg = ("String reference '{}' lacks of required 'value' variable "
                     "or is empty")
              raise SerializerError(msg.format(name))
  
          return value
docs: Serialize given datas to a string.
  
          Simply return the value from required variable``value``.
  
          Arguments:
              name (string): Name only used inside possible exception message.
              datas (dict): Datas to serialize.
  
          Returns:
              string: Value.