class_docstr: Base class of debug-wrapper session classes.
  
  Concrete classes that inherit from this class need to implement the abstract
  methods such as on_session_init, on_run_start and on_run_end.
class_docstr_tok: ["Base","class","of","debug-wrapper","session","classes",".","Concrete","classes","that","inherit","from","this","class","need","to","implement","the","abstract","methods","such","as","on_session_init",",","on_run_start","and","on_run_end","."]
docstr: Callback invoked on run() calls to the debug-wrapper session.
  
  This is a blocking callback.
  The invocation happens after the wrapper's run() call is entered,
  after an increment of run call counter.
  
  Args:
    request: (`OnRunStartRequest`) callback request object carrying
      information about the run call such as the fetches, feed dict, run
      options, run metadata, and how many `run()` calls to this wrapper
      session have occurred.
  
  Returns:
    An instance of `OnRunStartResponse`, carrying information to
      debug URLs used to watch the tensors.
docstr_tok: ["Callback","invoked","on","run","(",")","calls","to","the","debug-wrapper","session",".","This","is","a","blocking","callback",".","The","invocation","happens","after","the","wrapper","'s","run","(",")","call","is","entered",",","after","an","increment","of","run","call","counter",".","Args",":","request",":","(","`","OnRunStartRequest","`",")","callback","request","object","carrying","information","about","the","run","call","such","as","the","fetches",",","feed","dict",",","run","options",",","run","metadata",",","and","how","many","`","run","(",")","`","calls","to","this","wrapper","session","have","occurred",".","Returns",":","An","instance","of","`","OnRunStartResponse","`",",","carrying","information","to","debug","URLs","used","to","watch","the","tensors","."]
code: def on_run_start(self, request):
      """Callback invoked on run() calls to the debug-wrapper session.
  
      This is a blocking callback.
      The invocation happens after the wrapper's run() call is entered,
      after an increment of run call counter.
  
      Args:
        request: (`OnRunStartRequest`) callback request object carrying
          information about the run call such as the fetches, feed dict, run
          options, run metadata, and how many `run()` calls to this wrapper
          session have occurred.
  
      Returns:
        An instance of `OnRunStartResponse`, carrying information to
          debug URLs used to watch the tensors.
      """
  
imports: import abc
  import re
  import threading
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.python.client import session
  from tensorflow.python.debug.lib import debug_utils
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import stack
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.training import monitored_session
  from tensorflow.python.util import nest
  from tensorflow.python.util.compat import collections_abc
label_desc: Use image node_id 23 for calling the BaseDebugWrapperSession obj's underlying member method code with example usage: obj.on_run_start(request) without return types