ExpressionParameterValueExtractor { public static List<String> extractParameterValues(String expression) { List<String> parameterValues = Arrays.asList( expression.split(_FUNCTION_STRUCTURE_REGEX)); Stream<String> parameterValueStream = parameterValues.stream(); return parameterValueStream.filter( parameterValue -> Validator.isNotNull(parameterValue) ).collect( Collectors.toList() ); }  static List<String> extractParameterValues(String expression);  }
@Test public void testExtractParameterValues() { _assertParameterValueArray( _extractParameterValues("equals(Country, \"US\")"), Arrays.asList("Country", "\"US\"")); _assertParameterValueArray( _extractParameterValues("equals(sum(1,1), 2)"), Arrays.asList("1", "1", "2")); }