calledWith(f, s);
    }

    void check() {
      runTester();
      NullRejectingFromTo<?, ?> defaultFunction =
          (NullRejectingFromTo<?, ?>) getDefaultParameterValue(0);
      assertNotNull(defaultFunction);
      try {
        defaultFunction.apply(null);
        fail("Proxy Should have rejected null");
      } catch (NullPointerException expected) {
      }
    }
  }

        def file = module.getArtifact([type: artifactType, classifier: classifier]).file
        def function = Hashing.defaultFunction()
        switch (algo) {
            case ["sha1", "md5"]:
                def artifact = module.getArtifact([type: "${artifactType}.${algo}", classifier: classifier])
                if (artifact.file.exists()) {

        Hasher hasher = Hashing.defaultFunction().newHasher();
        hasher.putInt(CACHE_FORMAT);
        hasher.putInt(AsmConstants.MAX_SUPPORTED_JAVA_VERSION);
        gradleCoreInstrumentationTypeRegistry.getInstrumentedTypesHash().ifPresent(hasher::putHash);

    }

    List<TestFile> listCacheFiles() {
        cacheDir.listFiles().findAll { it.name ==~ /\p{XDigit}{${Hashing.defaultFunction().hexDigits}}/ }.sort()
    }

    void deleteCacheEntry(String cacheKey) {
        def entry = getTestFileCacheEntry(cacheKey)
        if (entry.file.exists()) {
            entry.file.deleteDir()
        }

    }

    TestFile getCacheDir() {
        Preconditions.checkNotNull(cacheDir)
    }

    List<TestFile> listCacheFiles() {
        cacheDir.listFiles().findAll { it.name ==~ /\p{XDigit}{${Hashing.defaultFunction().hexDigits}}/ }.sort()
    }

    void deleteCacheFiles() {
        listCacheFiles().each { it.delete() }
    }

    @Override
    WebAppContext getCustomHandler() {
        return webapp
    }

    private final static int DEFAULT_RETENTION_PERIOD_DAYS = 7

    def operations = new BuildOperationsFixture(executer, testDirectoryProvider)
    def hashStringLength = Hashing.defaultFunction().hexDigits

    abstract String getBuildCacheName();
    abstract void createBuildCacheEntry(String key, File value, long timestamp);
    abstract boolean existsBuildCacheEntry(String key);

        Hasher hasher = newHasher();
        hasher.put(hashable);
        return hasher.hash();
    }

    /**
     * The default hashing function.
     */
    public static HashFunction defaultFunction() {
        return DEFAULT;
    }

    /**
     * MD5 hashing function.
     */
    public static HashFunction md5() {
        return MD5;
    }

    /**