private void addToRefsHash(Address address, Reference ref,
			HashMap<Address, ArrayList<Reference>> refsHash) {
		ArrayList<Reference> refsList = refsHash.get(address);
		if (refsList == null) {
			refsList = new ArrayList<>();
			refsHash.put(address, refsList);
		}
		if (!refsList.contains(ref)) {
			refsList.add(ref);
		}
	}
@param program
@param fromAddress
@param operandIndex
@return
Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/ReferenceMerger.java