code: def _get_uuid():
      """Generate a unique identifier string"""
      return str(uuid.uuid4())
  
imports: from tabpy.tabpy_server.handlers import BaseHandler
  import logging
  import time
  from tabpy.tabpy_server.common.messages import Query, QuerySuccessful, QueryError, UnknownURI
  from hashlib import md5
  import uuid
  import json
  from tabpy.tabpy_server.common.util import format_exception
  import urllib
  from tornado import gen
  from tabpy.tabpy_server.handlers.util import AuthErrorStates
label_desc: Use image node_id 1 for calling a global function with example usage: _get_uuid() and returns: str