### Question:
GsonProvider implements MessageBodyReader<T>, MessageBodyWriter<T> { @Override public long getSize( T t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType ) { return -1; } GsonProvider(); @Override long getSize( T t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType  ); @Override boolean isWriteable( Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType ); @Override void writeTo( T object,
			Class<?> type,
			Type genericType,
			Annotation[] annotations,
			MediaType mediaType,
			MultivaluedMap<String, Object> httpHeaders,
			OutputStream entityStream ); @Override boolean isReadable( Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType ); @Override T readFrom( Class<T> type,
			Type genericType,
			Annotation[] annotations,
			MediaType mediaType,
			MultivaluedMap<String, String> httpHeaders,
			InputStream entityStream );  }### Answer:
@Test public void testGetSize() { GsonProvider<TestObject> testObjectProvider = new GsonProvider<TestObject>(); long size = testObjectProvider.getSize( mock( TestObject.class ), null, null, null, null ); assertThat( size ).isEqualTo( -1 ); }