static VirtualFile findChildThroughJar(@NotNull VirtualFile file, @NotNull String name, @NotNull NewVirtualFileSystem childFs) {
    VirtualFile child;
    if (name.equals(JarFileSystem.JAR_SEPARATOR) && childFs instanceof ArchiveFileSystem) {
      child = ((ArchiveFileSystem)childFs).getRootByLocal(file);
    }
    else {
      child = file.findChild(name);
    }
    return child;
  }
static VirtualFile findChildThroughJar(@NotNull VirtualFile file, @NotNull String name, @NotNull NewVirtualFileSystem childFs)