@Override
	public boolean retainAll(Collection<?> c) {
		return keys.retainAll(c);
	}
Construct a dynamic sorted tree set using a custom comparator to order the elements

@param comparator the comparator, providing a total ordering of the values
Ghidra/Debug/ProposedUtils/src/main/java/ghidra/generic/util/datastruct/DynamicSortedTreeSet.java