code: def group_names(self):
      return self.index.names
  
imports: from statsmodels.compat.python import lrange, lzip
  import numpy
  import pandas
  import statsmodels.tools.data
  from pandas import Index, MultiIndex
label_desc: Use image node_id 5 for calling the Grouping obj's underlying member method code with example usage: obj.group_names() and returns: self