private static DescriptiveTypeInfo newDescriptiveTypeInfo(
            DescriptiveTypeSignature typeSignature, DescriptiveTypeInfoProvider descriptiveTypeInfoProvider) {
        final Object descriptor = typeSignature.descriptor();
        assert descriptor instanceof Descriptor || descriptor instanceof EnumDescriptor;
        final DescriptiveTypeInfo descriptiveTypeInfo =
                descriptiveTypeInfoProvider.newDescriptiveTypeInfo(descriptor);
        return requireNonNull(descriptiveTypeInfo,
                              "descriptiveTypeInfoProvider.newDescriptiveTypeInfo() returned null");
    }
{@link DocServicePlugin} implementation that supports {@link GrpcService}s.
grpc/src/main/java/com/linecorp/armeria/internal/server/grpc/GrpcDocServicePlugin.java