code: def test_group_by_all_different():
      all_diferent = [{1: 1}, {2: 2}, {3: 3}, {4: 4}, {5: 5}, {6: 6}]
      d = {
          1: [{1: 1}],
          2: [{2: 2}],
          3: [{3: 3}],
          4: [{4: 4}],
          5: [{5: 5}],
          6: [{6: 6}],
      }
      assert _group_by(all_diferent, lambda s: list(s.keys())[0]) == d
  
imports: import pytest
  import numpy
  from sklearn_evaluation.util import _can_iterate, is_column_vector, is_row_vector, _group_by, _product, _mapping_to_tuple_pairs, map_parameters_in_fn_call
label_desc: Use image node_id 11 for calling a global function with example usage: test_group_by_all_different() without return types