@Override
	public int getReferenceCount() {
		lock.acquire();
		try {
			checkIsValid();
			int count = super.getReferenceCount();
			List<Long> thunkIds = functionMgr.getThunkFunctionIds(key);
			if (thunkIds != null) {
				count += thunkIds.size();
			}
			return count;
		}
		finally {
			lock.release();
		}
	}
Construct a new FunctionSymbol
@param symbolMgr the symbol manager.
@param cache symbol object cache
@param address the address for this symbol.
@param record the record for this symbol.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/symbol/FunctionSymbol.java