code: def get_train(self, maxtrain=None):
      return self.xb
  
file_path: faiss/benchs/bench_all_ivf/datasets_oss.py
imports: import time
  import numpy
  import faiss
  from faiss.contrib import datasets
label_desc: Use image node_id 4 for calling the DatasetCentroids obj's underlying member method code with example usage: obj.get_train(maxtrain) and returns: self