code: def test_blend_tuple_shape():
      """[Base] BlendIndex: test the tuple shape on generation."""
      tup = [
          (tri, tei) for tri, tei in BlendIndex(0.4, 0.5).generate(X)
      ]
  
      assert tup == [((0, 2), (2, 4))]
  
imports: import os
  import subprocess
  import numpy
  from mlens import config
  from mlens.utils import IdTrain
  from mlens.index import FoldIndex, BlendIndex, SubsetIndex, TemporalIndex, ClusteredSubsetIndex, FullIndex
  from mlens.index.base import partition, prune_train
label_desc: Use image node_id 23 for calling a global function with example usage: test_blend_tuple_shape() without return types