@NotNull
  public <R extends PsiElement, F_R extends T> PsiQuery<R> map(@NotNull final PsiFilter<F_R> preFilter,
                                                               @NotNull final Function<? super F_R, ? extends R> map) {
    return filter(preFilter).map(map);
  }
@NotNull
  public <R extends PsiElement, F_R extends T> PsiQuery<R> map(@NotNull final PsiFilter<F_R> preFilter,
                                                               @NotNull final Function<? super F_R, ? extends R> map)