private @NotNull UpToDateLineNumberProvider getProvider(@NotNull VirtualFile vf, @NotNull Document document) {
      UpToDateLineNumberProvider provider = myRecentlyChanged.get(vf);
      if (provider == null) {
        provider = new UpToDateLineNumberProviderImpl(document, myProject);
        myRecentlyChanged.put(vf, provider);
      }
      return provider;
    }
private @NotNull UpToDateLineNumberProvider getProvider(@NotNull VirtualFile vf, @NotNull Document document)