/** Visitor method: enter classes of a list of trees, returning a list of types. */
<T extends JCTree> List<Type> classEnter(List<T> trees, Env<AttrContext> env) {
ListBuffer<Type> ts = new ListBuffer<Type>();
for (List<T> l = trees; l.nonEmpty(); l = l.tail) {
Type t = classEnter(l.head, env);
if (t != null) ts.append(t);
}
return ts.toList();
}
