MultipartBody { public BinaryFile getBinaryFile(String key) { return _binaryFiles.get(key); } private  MultipartBody(
		Map<String, BinaryFile> binaryFiles,
		ObjectMapperProvider objectMapperProvider, Map<String, String> values); static MultipartBody of(
		Map<String, BinaryFile> binaryFiles,
		ObjectMapperProvider objectMapperProvider, Map<String, String> values); BinaryFile getBinaryFile(String key); byte[] getBinaryFileAsBytes(String key); T getValueAsInstance(String key, Class<T> clazz); Optional<T> getValueAsInstanceOptional(
			String key, Class<T> clazz); String getValueAsString(String key); Map<String, String> getValues();  }
@Test public void testGetBinaryFile() { BinaryFile binaryFile = new BinaryFile( "contentType", "fileName", null, 0); MultipartBody multipartBody = MultipartBody.of( Collections.singletonMap("file", binaryFile), __ -> _objectMapper, Collections.emptyMap()); assertThat(multipartBody.getBinaryFile("file"), is(binaryFile)); assertThat(multipartBody.getBinaryFile("null"), is(nullValue())); }