def resource = new AccessorBackedExternalResource(name, resourceAccessor, resourceUploader, resourceLister, true)

        when:
        expectResourceRead(name, "1234")
        def result = resource.withContentIfPresent(action)

        then:
        result.result == "result 1"
        result.bytesRead == 4
        1 * action.execute(_) >> { InputStream input -> input.text; "result 1" }
        0 * _

        when:

        def file = tmpDir.createFile("content")
        file.text = "1234"

        expect:
        def resource = new LocalFileStandInExternalResource(file, TestFiles.fileSystem())
        def result = resource.withContentIfPresent(new ExternalResource.ContentAndMetadataAction<String>() {
            @Override
            String execute(InputStream inputStream, ExternalResourceMetaData metaData) throws IOException {

        1 * repository.resource(new ExternalResourceName("thing.sha1"), true) >> remoteSha1
        1 * remoteSha1.withContentIfPresent(_) >> null
        1 * repository.withProgressLogging() >> progressLoggingRepo
        1 * progressLoggingRepo.resource(location, true) >> remoteResource
        1 * remoteResource.withContentIfPresent(_) >> { ExternalResource.ContentAndMetadataAction a ->
            a.execute(new ByteArrayInputStream(), remoteMetaData)

            ExternalResourceName sha1Location = location.append(".sha1");
            ExternalResource resource = delegate.resource(sha1Location, revalidate);
            ExternalResourceReadResult<HashCode> result = resource.withContentIfPresent(inputStream -> {
                String sha = IOUtils.toString(inputStream, StandardCharsets.US_ASCII);
                // Servers may return SHA-1 with leading zeros stripped

            @Override
            @Nullable
            public ExternalResourceReadResult<Metadata> call() {
                return repository.resource(metadataResource).withContentIfPresent(inputStream -> {
                    try {
                        return new MetadataXpp3Reader().read(inputStream, false);
                    } catch (Exception e) {