namespace tensorflow {
namespace {

constexpr char kInvalidExecutorGraphMsg[] =
    "functions must be of a single Graph with single op Islands: ";

}  // namespace

mlir::LogicalResult VerifyExportSuitable(mlir::ModuleOp module) {
  mlir::WalkResult result = module.walk([&](mlir::func::FuncOp function) {
    if (!llvm::hasSingleElement(function)) {
      function.emitError(kInvalidExecutorGraphMsg)