docstr: Return `int` of num classes
docstr_tok: ["Return","`","int","`","of","num","classes"]
code: def n_classes(self):
      """Return `int` of num classes"""
      raise NotImplementedError
  
file_path: auptimizer/src/aup/Proposer/eas/data_providers/base_provider.py
imports: import numpy
label_desc: Use image node_id 2 for calling the DataProvider obj's underlying member method code with example usage: obj.n_classes() without return types