code: def _define_event(callback_proto):
      available_events[callback_proto.__name__] = callback_proto
      return callback_proto
  
file_path: catboost/contrib/python/ipython/py2/IPython/core/events.py
imports: from __future__ import print_function
label_desc: Use image node_id 1 for calling a global function with example usage: _define_event(callback_proto) and returns: callback_proto