code: def get_index_desc(self, factory: str) -> Optional[IndexDescriptor]:
      for desc in self.index_descs:
          if desc.factory == factory:
              return desc
      return None
  
imports: import logging
  from copy import copy
  from dataclasses import dataclass
  from operator import itemgetter
  from statistics import median, mean
  from typing import Any, Dict, List, Optional
  from .utils import dict_merge
  from .index import Index, IndexFromCodec, IndexFromFactory
  from .descriptors import DatasetDescriptor, IndexDescriptor
  import faiss
  import numpy
  from scipy.optimize import curve_fit
label_desc: Use image node_id 3 for calling the Benchmark obj's underlying member method code with example usage: obj.get_index_desc(factory) and returns: None, desc