code: def test_pop():
      """[Parallel | Layer] Test pop"""
      # Popping one group leaves the layer intact
      g = layer.pop(0)
      assert layer.__stack__
      assert layer.__fitted__
      assert g1 is g
  
      # Popping both leaves if empty
      g = layer.pop(0)
      assert not layer.__stack__
      assert not layer.__fitted__
      assert g2 is g
  
      # Pushing fitted groups makes the layer fitted
      layer.push(g1, g2)
      assert layer.__fitted__
  
file_path: mlens/mlens/parallel/tests/test_b4_layer_push_pop.py
imports: import os
  import numpy
  from mlens.index import INDEXERS
  from mlens.testing.dummy import Data, ECM
  from mlens.utils.dummy import Scale, LogisticRegression
  from mlens.parallel import make_group, Layer, run
  from mlens.externals.sklearn.base import clone
label_desc: Use image node_id 6 for calling a global function with example usage: test_pop() without return types