class_docstr: This is a mixin class to support scalar data to RGBA mapping.
  The ScalarMappable makes use of data normalization before returning
  RGBA colors from the given colormap.
docstr: Add an entry to a dictionary of boolean flags
  that are set to True when the mappable is changed.
docstr_tok: ["Add","an","entry","to","a","dictionary","of","boolean","flags","that","are","set","to","True","when","the","mappable","is","changed","."]
code: def add_checker(self, checker):
      """
      Add an entry to a dictionary of boolean flags
      that are set to True when the mappable is changed.
      """
      self.update_dict[checker] = False
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import numpy
  from numpy import ma
  import matplotlib
  import matplotlib.colors
  import matplotlib.cbook
  from matplotlib._cm import datad
  from matplotlib._cm_listed import cmaps
label_desc: Use image node_id 12 for calling the ScalarMappable obj's underlying member method code with example usage: obj.add_checker(checker) without return types