### Question:
KnownMimeTypes { public static String getMimeTypeByExtension(String extension) { return EXTENSIONS.get(extension); } private  KnownMimeTypes(); static String getMimeTypeByExtension(String extension); static MediaType getMediaTypeByExtension(String extension); static final Multimap<String, String> EXTENSIONS_FOR_MIME; static final Map<String, String> EXTENSIONS; static final Set<String> COMPRESSED_MIME; }### Answer:
@Test public void testLoading() { assertThat(KnownMimeTypes.getMimeTypeByExtension("zip")).isEqualTo("application/zip"); assertThat(KnownMimeTypes.getMimeTypeByExtension("jpg")).isEqualTo("image/jpeg"); assertThat(KnownMimeTypes.getMimeTypeByExtension("json")).isEqualTo("application/json"); }
@Test public void testThatWeSupportTheSameSetOfExtensionsAsBefore() { for(Map.Entry<String, String> entry : OldKnownMimeTypes.EXTENSIONS.entrySet()) { if (KnownMimeTypes.getMimeTypeByExtension(entry.getKey()) == null) { assertThat(entry.getValue()).isEqualTo(KnownMimeTypes.EXTENSIONS.get(entry.getKey())); } } }