code: public FwAssistDirection assistAssistDirection() {
          if (assistDirection != null) {
              return assistDirection;
          }
          synchronized (this) {
              if (assistDirection != null) {
                  return assistDirection;
              }
              final FwAssistDirection direction = createAssistDirection();
              prepareAssistDirection(direction);
              assistDirection = direction;
          }
          return assistDirection;
      }
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