code: public static boolean nonstaticSelect(JCTree tree) {
          tree = skipParens(tree);
          if (!tree.hasTag(SELECT)) return false;
          JCFieldAccess s = (JCFieldAccess) tree;
          Symbol e = symbol(s.selected);
          return e == null || (e.kind != PCK && e.kind != TYP);
      }
docs: Return true if this is a nonstatic selection.