code: public String stripThreadName(String threadId)
      {
          if (threadId == null)
          {
              return null;
          }
          else
          {
              int index = threadId.lastIndexOf('@');
              return index >= 0 ? threadId.substring(0, index) : threadId;
          }
      }
docs: TestNG returns a compound thread ID that includes the thread name and its numeric ID,
  separated by an 'at' sign.  We only want to use the thread name as the ID is mostly
  unimportant and it takes up too much space in the generated report.
  @param threadId The compound thread ID.
  @return The thread name.