docstr: get number of processors given frequency
docstr_tok: ["get","number","of","processors","given","frequency"]
code: def get_kernels(self, freq: str):
      """get number of processors given frequency"""
      if isinstance(self["kernels"], Callable):
          return self["kernels"](freq)
      return self["kernels"]
  
imports: from __future__ import annotations
  import os
  import re
  import copy
  import logging
  import platform
  import multiprocessing
  from pathlib import Path
  from typing import Callable, Optional, Union
  from typing import TYPE_CHECKING
  from qlib.constant import REG_CN, REG_US, REG_TW
label_desc: Use image node_id 10 for calling the QlibConfig obj's underlying member method code with example usage: obj.get_kernels(freq) and returns: self, self