@Override
 public String verifyPath(String path) {
   GcsPath gcsPath = getGcsPath(path);
   checkArgument(gcsPath.isAbsolute(), "Must provide absolute paths for Dataflow");
   checkArgument(
       !gcsPath.getObject().contains("//"),
       "Dataflow Service does not allow objects with consecutive slashes");
   return gcsPath.toResourceName();
 }