### Question:
GroupingRequiredFilterFunctions { public static Collection<?> matchesInGroup(Object... args) { int positionFromRight = 0; if (args.length % 2 != 0) { Object lastArgument = args[args.length - 1]; positionFromRight = Integer.parseInt(lastArgument.toString()); } Collection<ValueTuple> leftSideMatches; Collection<ValueTuple> allMatches = new HashSet<>(); Object fieldValue1 = args[0]; String regex = args[1].toString(); if (fieldValue1 instanceof Iterable) { leftSideMatches = EvaluationPhaseFilterFunctions.getAllMatches((Iterable) fieldValue1, regex); } else { leftSideMatches = EvaluationPhaseFilterFunctions.getAllMatches(fieldValue1, regex); } for (ValueTuple currentMatch : leftSideMatches) { String matchFieldName = ValueTuple.getFieldName(currentMatch); String context = EvaluationPhaseFilterFunctions.getMatchToRightOfPeriod(matchFieldName, positionFromRight); for (int i = 2; i < args.length; i += 2) { if (args[i] instanceof Iterable) { for (Object fv : (Iterable) args[i]) { manageMatchesInGroupRemainingArgs(fv, args[i + 1].toString(), context, allMatches, currentMatch); } } else if (args[i] instanceof ValueTuple) { manageMatchesInGroupRemainingArgs(args[i], args[i + 1].toString(), context, allMatches, currentMatch); } } } if (allMatches.size() < args.length / 2) { allMatches.clear(); } return Collections.unmodifiableCollection(allMatches); }  static Collection<?> getGroupsForMatchesInGroup(Object... args); static Collection<?> matchesInGroup(Object... args); static Collection<?> matchesInGroupLeft(Object... args); static Collection<ValueTuple> atomValuesMatch(Object... fields); static Collection<ValueTuple> atomValuesMatch(Iterable<?>... fields); static final String GROUPING_REQUIRED_FUNCTION_NAMESPACE; }### Answer:
@Test public void testMatchesInGroup() { Assert.assertTrue(GroupingRequiredFilterFunctions.matchesInGroup( makeValueTuple("ALPHA.1,BAR,bar"), "bar", makeValueTuple("GAMMA.1,BAZ,baz"), "baz").size() == 2); Assert.assertTrue(GroupingRequiredFilterFunctions.matchesInGroup( Collections.singleton(makeValueTuple("ALPHA.1,BAR,bar")), "bar", Collections.singleton(makeValueTuple("GAMMA.1,BAZ,baz")), "baz").size() == 2); }