CRC32Function implements Function<String> { @Override public String apply(List<Object> objects) { String strValue = String.valueOf(objects.get(0)); CRC32 crc = new CRC32(); crc.update(strValue.getBytes()); return Long.toHexString(crc.getValue()); }  @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(Collections.singletonList("Hello World!")), equalTo("1c291ca3")); }