code: def MapRequestParams(params, request_type):
      
      new_params = dict(params)
      for param_name, value in params.items():
          field_remapping = encoding.GetCustomJsonFieldMapping(
              request_type, python_name=param_name)
          if field_remapping is not None:
              new_params[field_remapping] = new_params.pop(param_name)
              param_name = field_remapping
          if isinstance(value, messages.Enum):
              new_params[param_name] = encoding.GetCustomJsonEnumMapping(
                  type(value), python_name=str(value)) or str(value)
      return new_params
docs: Perform any renames/remappings needed for URL construction.
  
      Currently, we have several ways to customize JSON encoding, in
      particular of field names and enums. This works fine for JSON
      bodies, but also needs to be applied for path and query parameters
      in the URL.
  
      This function takes a dictionary from param names to values, and
      performs any registered mappings. We also need the request type (to
      look up the mappings).
  
      Args:
        params: (dict) Map from param names to values
        request_type: (protorpc.messages.Message) request type for this API call
  
      Returns:
        A new dict of the same size, with all registered mappings applied.