code: @Override
      public boolean cancel(boolean mayInterruptIfRunning) {
  
          if (m_isDone == true) {
              return false;
          }
          m_isDone = true;
  
          try {
              m_cancelResult = m_schedFuture.cancel(mayInterruptIfRunning);
  
              m_pendingException = new CancellationException();
          } finally {
              // Let get() finish
              this.m_coordinationLatch.countDown();
          }
  
          return m_cancelResult;
      }
docs: /*
  (non-Javadoc)
  
  @see java.util.concurrent.Future#cancel(boolean)