code: def get_ie(instance, key, data):
      
      if not instance.print_:
          return dict()
      if len(data) < instance.minlen or len(data) > instance.maxlen:
          if data:
              return {'<invalid: {0} byte(s)>'.format(len(data)): ' '.join(format(x, '02x') for x in data)}
          return {'<invalid: no data>': data}
      return {instance.name: instance.print_(key, data)}
docs: http://git.kernel.org/cgit/linux/kernel/git/jberg/iw.git/tree/scan.c?id=v3.17#n981.
  
      Positional arguments:
      instance -- `ie_print` class instance.
      key -- corresponding `ieprinters` dictionary key for the instance.
      data -- bytearray data to read.
  
      Returns:
      Dictionary of parsed data with string keys.