public static Set<String> extractEmbeddedFileReferences(final VirtualFile vFile,
                                                          final @Nullable VirtualFile contextVFile,
                                                          final PsiManager psiManager,
                                                          final String url) {
    return ReadAction.compute(() -> {
      PsiFile file = psiManager.findFile(vFile);

      if (file instanceof XmlFile) {
        PsiFile contextFile = contextVFile != null ? psiManager.findFile(contextVFile) : null;
        return extractEmbeddedFileReferences((XmlFile)file, contextFile instanceof XmlFile ? (XmlFile)contextFile : null, url);
      }

      return Collections.emptySet();
    });
  }
public static Set<String> extractEmbeddedFileReferences(final VirtualFile vFile,
                                                          final @Nullable VirtualFile contextVFile,
                                                          final PsiManager psiManager,
                                                          final String url)