### Question:
Hints implements Serializable { public Hints platform(Platform platform) { set(PLATFORM, platform); return this; } Hints();  Hints(@NonNull Hints orig); void set(String key, Serializable value); Optional<Serializable> get(final String key); boolean getBoolean(final String key); @Override String toString(); @Override boolean equals(Object o); Map<String, Serializable> getAll(); static Hints readOnly(); Hints readOnly(boolean ro); static boolean isRepoReadOnly(Hints hints); static Hints readWrite(); static Hints repository(@NonNull URI repoURI); Hints uri(URI repoURI); Hints platform(Platform platform); static final String OBJECTS_READ_ONLY; static final String REMOTES_READ_ONLY; static final String REPOSITORY_URL; static final String REPOSITORY_NAME; static final String PLATFORM; }### Answer:
@Test public void testPlatform() { @SuppressWarnings("serial") Platform platform = new Platform() { public @Override File pwd() { return null; } public @Override void setWorkingDir(File workingDir) { } public @Override String whoami() { return null; } public @Override long currentTimeMillis() { return 0; } public @Override long nanoTime() { return 0; } public @Override File getUserHome() { return null; } public @Override int timeZoneOffset(long timeStamp) { return 0; } public @Override int availableProcessors() { return 0; } }; Hints hints = new Hints(); assertFalse(hints.get(Hints.PLATFORM).isPresent()); hints.platform(platform); assertEquals(platform, hints.get(Hints.PLATFORM).get()); }