Add option to AreIn to perform a strict test and return false if the collection is null or empty

[n3101]

AreIn tests whether supplied values are all in a given collection, but also returns true if the collection is null or empty. This behaviour was intended - it is tested for and documented. The rationale for this has been lost.

Retain this as the default behaviour, but add an option to perform the strict test and return false if null or empty

[t92549]

The implementation lives here:

koryphe/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/AreIn.java

Lines 82 to 83 in 8f04588

	public boolean test(final Collection<?> input) {
	return null == allowedValues || allowedValues.isEmpty() || (null != input && allowedValues.containsAll(input));

Some kind of option could be added to change this, similar to how orEqualTo is used in IsLessThan:

koryphe/core/src/main/java/uk/gov/gchq/koryphe/impl/predicate/IsLessThan.java

Line 40 in 8f04588

private boolean orEqualTo;

[shlokam]

@n3101 @t92549 Can you assign this issue to me?

[n3101]

@shlokam I certainly can. Welcome!