class_docstr: Base callback class.
  
  .. note::
  
      All callbacks should override this class.
class_docstr_tok: ["Base","callback","class",".","..","note",":",":","All","callbacks","should","override","this","class","."]
docstr: Perform some action with the given state as context at the start of each epoch.
  
  Args:
      state (dict): The current state dict of the :class:`.Trial`.
docstr_tok: ["Perform","some","action","with","the","given","state","as","context","at","the","start","of","each","epoch",".","Args",":","state","(","dict",")",":","The","current","state","dict","of","the",":","class",":","`",".Trial","`","."]
code: def on_start_epoch(self, state):
      """Perform some action with the given state as context at the start of each epoch.
  
      Args:
          state (dict): The current state dict of the :class:`.Trial`.
      """
      pass
  
imports: import functools
  import traceback
  import warnings
  import torch
  from packaging import version
  import torchbearer
  import sys
label_desc: Use image node_id 6 for calling the Callback obj's underlying member method code with example usage: obj.on_start_epoch(state) without return types