class_docstr: DEPRECATED since IPython 5.0
  
  A null inputhook that doesn't need to do anything
class_docstr_tok: ["DEPRECATED","since","IPython","5.0","A","null","inputhook","that","does","n't","need","to","do","anything"]
code: def enable(self, app=None):
      warn(
          "This function is deprecated since IPython 5.0 and will be removed in future versions.",
          DeprecationWarning,
          stacklevel=2,
      )
  
imports: import os
  import platform
  import sys
  from distutils.version import LooseVersion
  from warnings import warn
label_desc: Use image node_id 1 for calling the NullInputHook obj's underlying member method code with example usage: obj.enable(app) without return types