@Override
  public void registerReferenceProviders(@NotNull PsiReferenceRegistrar registrar) {

    registrar.registerReferenceProvider(new PsiElementPattern.Capture<>(PsiElement.class) {
      @Override
      public boolean accepts(@Nullable Object o, ProcessingContext context) {
        return o instanceof PsiLiteralValue && ((PsiLiteralValue)o).getValue() instanceof String;
      }
    }, new ArbitraryPlaceUrlReferenceProvider(), PsiReferenceRegistrar.LOWER_PRIORITY);
  }
@Override
  public void registerReferenceProviders(@NotNull PsiReferenceRegistrar registrar)