class_docstr: Hooks are less powerful than callbacks so the conversion is incomplete.
  It only converts the ``before_run/after_run`` calls.
  
  This is only for internal implementation of
  ``before_run/after_run`` callbacks.
  You shouldn't need to use this.
class_docstr_tok: ["Hooks","are","less","powerful","than","callbacks","so","the","conversion","is","incomplete",".","It","only","converts","the","``","before_run\/after_run","``","calls",".","This","is","only","for","internal","implementation","of","``","before_run\/after_run","``","callbacks",".","You","should","n't","need","to","use","this","."]
code: def before_run(self, ctx):
      return self._cb.before_run(ctx)
  
imports: import tensorflow
  from ..compat import tfv1
  from ..utils.develop import HIDE_DOC
  from .base import Callback
label_desc: Use image node_id 2 for calling the CallbackToHook obj's underlying member method code with example usage: obj.before_run(ctx) and returns: self