class_docstr: Generic abstract class for a test dataset 
class_docstr_tok: ["Generic","abstract","class","for","a","test","dataset"]
docstr: runs the previous and checks the sizes of the matrices 
docstr_tok: ["runs","the","previous","and","checks","the","sizes","of","the","matrices"]
code: def check_sizes(self):
      """runs the previous and checks the sizes of the matrices"""
      assert self.get_queries().shape == (self.nq, self.d)
      if self.nt > 0:
          xt = self.get_train(maxtrain=123)
          assert xt.shape == (123, self.d), "shape=%s" % (xt.shape,)
      assert self.get_database().shape == (self.nb, self.d)
      assert self.get_groundtruth(k=13).shape == (self.nq, 13)
  
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 9 for calling the Dataset obj's underlying member method code with example usage: obj.check_sizes() without return types