code: def _merge_values(self, to_values, from_values):
          
          if from_values is not None:
              for k, v in from_values.items():
                  if k in to_values and isinstance(to_values[k], dict):
                      self._merge_values(to_values[k], v) # merge
                  else:
                      to_values[k] = v # replaces instead of merge
          return to_values
docs: Merges two dictionaries of values recursively. This is a very naive
          implementation that expects the two dictionaries to be fairly similar 
          in structure.
  
          @param to_values destination dictionary
          @param from_values dictionary with values to copy