code: private int handleNewSessions() {
          int addedSessions = 0;
  
          for (;;) {
              T session = newSessions.poll();
  
              if (session == null) {
                  // All new sessions have been handled
                  break;
              }
  
              if (addNow(session)) {
                  // A new session has been created 
                  addedSessions++;
              }
          }
  
          return addedSessions;
      }
docs: Loops over the new sessions blocking queue and returns
  the number of sessions which are effectively created
  
  @return The number of new sessions