code: public OperationBuilder parameters(final List<Parameter> parameters) {
      List<Parameter> source = nullToEmptyList(parameters);
      List<Parameter> destination = new ArrayList<>(this.parameters);
      ParameterMerger merger = new ParameterMerger(destination, source);
      this.parameters = new ArrayList<>(merger.merged());
      return this;
    }
docs: Updates the input parameters this operation needs
  
  @param parameters - input parameter definitions
  @return this