code: def interaction(self, other):
      if isinstance(other, self.__class__):
          other = other.group
      return self.__class__((self, other))
  
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 Group obj's underlying member method code with example usage: obj.interaction(other) and returns: self