@Override
  public final @NotNull T getRootElement() {
    if (!isValid()) {
      PsiUtilCore.ensureValid(myFile);
      throw new AssertionError(this + " is not equal to " + myManager.getFileElement(myFile));
    }
    return (T)getRootHandler().getProxy();
  }
@Override
  public final @NotNull T getRootElement()