CharFunction implements Function<String> { @Override public String apply(List<Object> objects) { StringBuilder stringBuilder = new StringBuilder(); objects.stream() .map(c -> (char) Integer.valueOf(String.valueOf(c)).intValue()) .forEach(stringBuilder::append); return stringBuilder.toString(); }  @Override Set<String> validateInput(List<Object> args); @Override Class<String> getReturnType(); @Override FunctionName getName(); @Override String apply(List<Object> objects); @Override String getSignature(); @Override String getDescription();  }
@Test public void apply() throws Exception { assertThat(function.apply(Arrays.asList(116, 101, 120, 116)), equalTo("text")); }