private Namespace findExternalNamespaceSymbol(SymbolTable symbolTable, String name,
			Namespace currentNamespace) {
		List<Symbol> symbols = symbolTable.getSymbols(name, currentNamespace);
		for (Symbol symbol : symbols) {
			Object object = symbol.getObject();
			if (object instanceof Namespace) {
				Namespace namespace = (Namespace) object;
				if (namespace.isExternal()) {
					return namespace;
				}
			}
		}
		return null;
	}
Changes the function's parameter indicated by index to be a stack
parameter with the indicated stack offset.
@param func the function
@param index the index of an existing parameter
@param stackOffset the stack offset for this parameter
Ghidra/Features/Base/src/test.slow/java/ghidra/app/merge/listing/AbstractExternalMergerTest.java