code: @Override
      public synchronized boolean isCompletionPortValid(long completionPort) {
          for (Long port : completionPorts) {
              if (port.longValue() == completionPort) {
                  return true;
              }
          }
          return false;
      }
docs: /*
  @see com.ibm.io.async.IAsyncProvider#isCompletionPortValid(long)