code: private static Message generateHeader(HeaderValues param) {
  
          HeaderFields header = new HeaderFields();
          setValues(header, param);
  
          Message headerMsg = header.unwrap();
  
          for (String comment : param.comments) {
              headerMsg.addComment(comment);
          }
  
          return headerMsg;
      }
docs: This, more general, generate method is private, along with the
  HeaderValues object, until we decide what the public API should be.
  
  @param param
  @return