code: public static KbServerSideException fromThrowable(Throwable cause) {
      return (cause instanceof KbServerSideException)
                     ? (KbServerSideException) cause
                     : new KbServerSideException(cause);
    }
docs: Converts a Throwable to a KbServerSideException. If the Throwable is a
  KbServerSideException, it will be passed through unmodified; otherwise, it will be wrapped
  in a new KbServerSideException.
  
  @param cause the Throwable to convert
  
  @return a KbServerSideException