@Override
	public void removeAssociation(Reference ref) {
		lock.acquire();
		try {
			setSymbolID(ref, -1);
			program.setObjChanged(ProgramEvent.SYMBOL_ASSOCIATION_REMOVED, ref.getFromAddress(),
				ref, null, null);
		}
		catch (IOException e) {
			program.dbError(e);
		}
		finally {
			lock.release();
		}
	}
Symbol has been added
@param sym new symbol
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/references/ReferenceDBManager.java