message: add out-of-class definition for FinalizeDatasetOp::kHasCapturedRef
diff: @@ -31,6 +31,7 @@ namespace data {
  /* static */ constexpr const char* const FinalizeDatasetOp::kInputDataset;
  /* static */ constexpr const char* const FinalizeDatasetOp::kOutputTypes;
  /* static */ constexpr const char* const FinalizeDatasetOp::kOutputShapes;
  +/* static */ constexpr const char* const FinalizeDatasetOp::kHasCapturedRef;
  namespace {
  