docstr: The percent of cores currently in use.
docstr_tok: ["The","percent","of","cores","currently","in","use","."]
code: def percent_cores_used(self) -> float:
      """The percent of cores currently in use."""
      return self.used_cores_mcpu_nonnegative / self.cores_mcpu
  
imports: import base64
  import json
  import logging
  import secrets
  from typing import Dict, Optional
  import aiohttp
  from gear import Database, transaction
  from hailtop import httpx
  from hailtop.humanizex import naturaldelta_msec
  from hailtop.utils import retry_transient_errors, time_msecs, time_msecs_str
  from ..cloud.utils import instance_config_from_config_dict
  from ..globals import INSTANCE_VERSION
  from ..instance_config import InstanceConfig
label_desc: Use image node_id 7 for calling the Instance obj's underlying member method code with example usage: obj.percent_cores_used() and returns: unknown