code: private TypedScope getScopeDeclaredIn() {
      if (declarationScope != null) {
        return declarationScope;
      }
  
      int dotIndex = fnName.indexOf('.');
      if (dotIndex != -1) {
        String rootVarName = fnName.substring(0, dotIndex);
        TypedVar rootVar = enclosingScope.getVar(rootVarName);
        if (rootVar != null) {
          return rootVar.getScope();
        }
      }
      return enclosingScope;
    }
docs: The scope that we should declare this function in, if it needs
  to be declared in a scope. Notice that TypedScopeCreator takes
  care of most scope-declaring.