@Nullable
  public static PhpClass getInterface(PhpIndex phpIndex, String className) {

    // api workaround
    if (!className.startsWith("\\")) {
      className = "\\" + className;
    }

    Collection<PhpClass> classes = phpIndex.getInterfacesByFQN(className);
    return classes.isEmpty() ? null : classes.iterator().next();
  }
 @Nullable
 public static PhpClass getClass(PhpIndex phpIndex, String className) {
   Collection<PhpClass> classes = phpIndex.getClassesByFQN(className);
   return classes.isEmpty() ? null : classes.iterator().next();
 }