@Override
	public void removeOperandReference(int opIndex, Address refAddr) {
		validate(lock);
		Reference ref = refMgr.getReference(address, refAddr, opIndex);
		if (ref != null) {
			program.getReferenceManager().delete(ref);
		}
	}
@see ghidra.program.model.listing.CodeUnit#addOperandReference(int,
     ghidra.program.model.address.Address,
     ghidra.program.model.symbol.RefType, SourceType)
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CodeUnitDB.java