code: public org.tensorflow.framework.OptimizerOptions.Level getOptLevel() {
      org.tensorflow.framework.OptimizerOptions.Level result = org.tensorflow.framework.OptimizerOptions.Level.valueOf(optLevel_);
      return result == null ? org.tensorflow.framework.OptimizerOptions.Level.UNRECOGNIZED : result;
    }
docs: <code>optional .tensorflow.OptimizerOptions.Level opt_level = 3;</code>