@SuppressWarnings({ "unchecked" })
	protected int compare(E k1, E k2) {
		if (comparator == null) {
			return ((Comparable) k1).compareTo(k2);
		}
		return comparator.compare(k1, k2);
	}
@ SuppressWarnings ( { "unchecked" } ) protected int compare ( E k1 , E k2 ) { if ( comparator == null ) { return ( ( Comparable ) k1 ) . compareTo ( k2 ) ; } return comparator . compare ( k1 , k2 ) ; }
Compares two keys using the correct comparison method for this
collection.