code: def get_json_argument(self, name, default=None):
          
  
          if default is None:
              default = self._ARG_DEFAULT
          if not self.request.arguments:
              self.load_json()
          if name not in self.request.arguments:
              if default is self._ARG_DEFAULT:
                  msg = "Missing argument '%s'" % name
                  self.logger.debug(msg)
                  self.raise_error(400, msg)
              self.logger.debug("Returning default argument %s, as we couldn't "
                                "find '%s' in %s" % (default, name,
                                                     self.request.arguments))
              return default
          arg = self.request.arguments[name]
          return arg
docs: Find and return the argument with key 'name'
          from JSON request data. Similar to Tornado's get_argument() method.
  
          :param str name: The name of the json key you want to get the value for
          :param bool default: The default value if nothing is found
          :returns: value of the argument name request