code: def test_collect():
      """[Parallel | Learner] Testing multiple collections"""
      lr = Learner(OLS(), indexer=data.indexer, name="lr")
      lr.__no_output__ = False
      a = _run(lr, "fit", X, y, return_preds=True)
      b = _run(lr, "fit", X, y, refit=False, return_preds=True)
      c = _run(lr, "transform", X, y, return_preds=True)
      d = _run(lr, "transform", X, y)
  
      np.testing.assert_array_equal(a, b)
      np.testing.assert_array_equal(a, c)
      np.testing.assert_array_equal(a, d)
  
imports: import numpy
  from mlens.testing import Data, EstimatorContainer
  from mlens.parallel import Group, Learner, Pipeline, run
  from mlens.utils.dummy import OLS, Scale
  from mlens.externals.sklearn.base import clone
label_desc: Use image node_id 3 for calling a global function with example usage: test_collect() without return types