code: @Override
    public State getFinalState() {
      ConstructState state = new ConstructState();
      if (this.converter != null) {
        state.addConstructState(Constructs.CONVERTER, new ConstructState(this.converter.getFinalState()));
      }
      if (this.rowLevelPolicyChecker != null) {
        state.addConstructState(Constructs.ROW_QUALITY_CHECKER,
            new ConstructState(this.rowLevelPolicyChecker.getFinalState()));
      }
      if (this.writer.isPresent() && this.writer.get() instanceof FinalState) {
        state.addConstructState(Constructs.WRITER, new ConstructState(((FinalState) this.writer.get()).getFinalState()));
      }
      return state;
    }
docs: {@inheritDoc}.
  
  @return a {@link org.apache.gobblin.configuration.State} object storing merged final states of constructs
  used in this {@link Fork}