class_docstr: Holder class with indexing
  
      
code: def __getitem__(self, idx):
      return self.tuple[idx]
  
file_path: statsmodels/statsmodels/stats/base.py
imports: from statsmodels.compat.python import lzip
  import numpy
  from statsmodels.tools.testing import Holder
label_desc: Use image node_id 3 for calling the HolderTuple obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: self