mlir::OpBuilder builder_at_begin(builder_.getBlock(),
                                     builder_.getBlock()->begin());
    auto source_op =
        builder_at_begin.create<mlir::tf_executor::NextIterationSourceOp>(
            loc, operands[0].getType(), result.attributes);
    return builder_.create<mlir::tf_executor::NextIterationSinkOp>(
        loc, source_op.getToken(), operands, result.attributes);
  }