code: def _add_lowercase(d):
      """Returns a dictionary with the lowercase keys and values entered."""
      retval = d.copy()
      retval.update({k.lower(): v.lower() for k, v in d.items()})
      return retval
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
label_desc: Use image node_id 1 for calling a global function with example usage: _add_lowercase(d) and returns: retval