class_docstr: Class that creates a callable object to retrieve events in a
  blocking way.
docstr: For base class, this just appends an event to events.
docstr_tok: ["For","base","class",",","this","just","appends","an","event","to","events","."]
code: def add_event(self, event):
      """For base class, this just appends an event to events."""
      self.events.append(event)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import matplotlib.lines
  import logging
label_desc: Use image node_id 5 for calling the BlockingInput obj's underlying member method code with example usage: obj.add_event(event) without return types