### Question:
TypeDecoder { static Utf8String decodeUtf8String(String input, int offset, long chainId) { DynamicBytes dynamicBytesResult = decodeDynamicBytes(input, offset, chainId); byte[] bytes = dynamicBytesResult.getValue(); return new Utf8String(new String(bytes, StandardCharsets.UTF_8)); }  static T decode(
            String input, int offset, TypeReference<T> typeReference,long chainId);  }### Answer:
@Test public void testUtf8String() { assertThat(TypeDecoder.decodeUtf8String( "000000000000000000000000000000000000000000000000000000000000000d" + "48656c6c6f2c20776f726c642100000000000000000000000000000000000000", 0, NetworkParameters.MainNetParams.getChainId()), is(new Utf8String("Hello, world!"))); }