"Mismatch between signature def inputs/outputs and main function "
        "arguments.");
    return {};
  }
  // Exported method name.
  auto exported_name =
      main_op->getAttrOfType<mlir::ArrayAttr>(kTfSavedModelExportedNamesAttr);
  if (exported_name.empty()) {
    main_op.emitError("Empty exported names for main Function.");
    return {};
  }
  // Fill the SignatureDefData container.