this.error = error
    }
}

abstract class InputsSpec {

    abstract InputsSpec expect(Matcher<String> input)

    abstract InputsSpec expectNone()

    abstract InputsSpec ignoreUnexpected()

    static final InputsSpec IGNORING = new InputsSpec() {

        @Override
        InputsSpec expect(Matcher<String> input) {
            new ExpectingSome().expect(input)
        }

  for (auto input : llvm::zip(getOperandTypes(), getInputSpecs())) {
    Type inputType = std::get<0>(input);
    Attribute inputSpec = std::get<1>(input);
    if (!isValidQuantizationSpec(inputSpec, inputType)) {
      return emitOpError() << "has incompatible specification " << inputSpec
                           << " and input type " << inputType;
    }
  }

  for (auto input : llvm::zip(getOperandTypes(), getInputSpecs())) {
    Type inputType = std::get<0>(input);
    Attribute inputSpec = std::get<1>(input);
    if (!isValidQuantizationSpec(inputSpec, inputType)) {
      return emitOpError() << "has incompatible specification " << inputSpec
                           << " and input type " << inputType;
    }
  }