Collection<? extends ExternalEntityIndexableIterator> createExternalEntityIterators(@NotNull EntityPointer<E> reference,
                                                                                      @NotNull Collection<? extends VirtualFile> roots,
                                                                                      @NotNull Collection<? extends VirtualFile> sourceRoots,
                                                                                      @Nullable D customization);
Collection<? extends ExternalEntityIndexableIterator> createExternalEntityIterators(@NotNull EntityPointer<E> reference,
                                                                                      @NotNull Collection<? extends VirtualFile> roots,
                                                                                      @NotNull Collection<? extends VirtualFile> sourceRoots,
                                                                                      @Nullable D customization)