@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((first == null) ? 0 : first.hashCode());
		return result;
	}
DominantPair is a pair where the key is responsible for equality and hashCode (and the value of
the pair doesn't matter at all).  This is useful when you need the pair itself to function as a
key in a Map or value in a Set.

@param <K> the key type
@param <V> the value type
Ghidra/Framework/Generic/src/main/java/generic/DominantPair.java