code: def test_group_by_category_ints():
      assert helpers.group_by_category([1, 1, 2, 3]) == [0, 0, 1, 2]
  
file_path: hypertools/tests/test_helpers.py
imports: import numpy
  import hypertools._shared.helpers
label_desc: Use image node_id 2 for calling a global function with example usage: test_group_by_category_ints() without return types