code: public static boolean isValidFileName(@Nullable String name) {
          return !TextUtils.isEmpty(name)
                  && !name.contains("/")
                  && !name.equals(".")
                  && !name.equals("..");
      }
docs: Name is validated to be non-null, non-empty and not containing any
  slashes.
  
  @param name The name of the folder the user wishes to create.