code: ValidationResult mergeMultiValuePropertyForKey(JSONArray currentValues, JSONArray newValues, String action, String key) {
          ValidationResult vr = new ValidationResult();
          Boolean remove = REMOVE_VALUES_OPERATION.equals(action);
          vr = _mergeListInternalForKey(key, currentValues, newValues, remove, vr);
          return vr;
      }
docs: Merges a multi-value property JSONArray.
  <p/>
  trims to max length currently 100 items, on a FIFO basis
  <p/>
  please clean the key and newValues values before calling this
  
  @param currentValues current JSONArray property value
  @param newValues     JSONArray of new values
  @param action        String the action to take relative to the new values ($add, $remove)
  @param key           String the property key
  @return The {@link ValidationResult} object containing the merged value,
  and the error code(if any)