code: protected synchronized void addContent(Artifact record, String filename) {
          if (record != null) {
              if (filename.endsWith(".jar")) {
                  // this is an embedded archive
                  embedded.add(record);
              } else {
                  contents.add(record);
              }
          }
      }
docs: Synchronized method for adding a new conent
  
  @param record
  @param filename