private boolean hasAllFunctionRefs(Collection<Address> refs) throws CancelledException {

		if (refs == null || refs.isEmpty()) {
			return false;
		}

		for (Address ref : refs) {
			monitor.checkCancelled();
			if (ref.isExternalAddress()) {
				continue;
			}
			Function function = functionManager.getFunctionContaining(ref);
			if (function == null) {
				return false;
			}
		}
		return true;
	}
method to find the main vtable for the given typeinfo and if any, add the
construction ones to the passed in list

@param typeinfo
@param map
@param constructionVtables
@param numBaseRefs
@return address of main vtable for this class
@throws CancelledException
Ghidra/Features/Decompiler/ghidra_scripts/classrecovery/RTTIGccClassRecoverer.java