docstr: Add a pre-save/load callback for weights files and return its handle.
  If the callback was already added, return the existing handle.
  
  :param handle: A callback handle returned from :meth:WeightsFileHandler.add_pre_callback
  :return True if callback removed, False otherwise
docstr_tok: ["Add","a","pre-save\/load","callback","for","weights","files","and","return","its","handle",".","If","the","callback","was","already","added",",","return","the","existing","handle",".",":","param","handle",":","A","callback","handle","returned","from",":","meth",":","WeightsFileHandler.add_pre_callback",":","return","True","if","callback","removed",",","False","otherwise"]
code: def remove_pre_callback(cls, handle):
      # type: (int) -> bool
      """
      Add a pre-save/load callback for weights files and return its handle.
      If the callback was already added, return the existing handle.
  
      :param handle: A callback handle returned from :meth:WeightsFileHandler.add_pre_callback
      :return True if callback removed, False otherwise
      """
      return cls._remove_callback(handle, cls._model_pre_callbacks)
  
imports: import os
  import shutil
  import sys
  import threading
  from enum import Enum
  from random import randint
  from tempfile import mkstemp
  from typing import TYPE_CHECKING, Callable, Dict, Optional, Any, Union
  import six
  from pathlib2 import Path
  from ...backend_interface.model import Model
  from ...config import running_remotely
  from ...debugging.log import get_logger
  from ...model import InputModel, OutputModel
label_desc: Use image node_id 5 for calling the WeightsFileHandler obj's underlying member method code with example usage: obj.remove_pre_callback(cls, handle) and returns: cls