  explicit SparseSegmentReductionMeanOp(OpKernelConstruction* context)
      : SparseSegmentReductionOpBase<Device, T>(
            context, true /*is_mean*/, false /*is_sqrtn*/,
            false /* has_num_segments */, T(0) /* default_value */) {}
  explicit SparseSegmentReductionMeanOp(OpKernelConstruction* context)
      : SparseSegmentReductionOpBase<Device, T>(
            context, true  , false  ,
            false  , T(0)  ) {}