code: public void addOutputProperty(String name, String value) {
          if (name == null) {
              throw new IllegalArgumentException("name must not be null");
          }
          if (value == null) {
              throw new IllegalArgumentException("value must not be null");
          }
          output.setProperty(name, value);
      }
docs: Add a named output property.
  
  @param name name of the property - must not be null
  @param value value of the property - must not be null