class_docstr: Generic abstract class for a test dataset 
class_docstr_tok: ["Generic","abstract","class","for","a","test","dataset"]
docstr: return the queries as a (nq, d) array 
docstr_tok: ["return","the","queries","as","a","(","nq",",","d",")","array"]
code: def get_queries(self):
      """return the queries as a (nq, d) array"""
      raise NotImplementedError()
  
imports: import os
  import numpy
  import faiss
  from .vecs_io import fvecs_read, ivecs_read, bvecs_mmap, fvecs_mmap
  from .exhaustive_search import knn
label_desc: Use image node_id 2 for calling the Dataset obj's underlying member method code with example usage: obj.get_queries() without return types