class_docstr: Class that creates a callable object to retrieve a single mouse or
  keyboard click
code: def __init__(self, fig):
      BlockingInput.__init__(
          self,
          fig=fig,
          eventslist=("button_press_event", "key_press_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 1 to create a new BlockingKeyMouseInput object from inherited base classes: BlockingInput with example: obj = BlockingKeyMouseInput(fig)