code: def test_extend():
      l = DogmaticList([1, 2])
      l.extend([3, 4])
      assert l == [1, 2]
  
imports: import pytest
  from sacred.config.custom_containers import DogmaticDict, DogmaticList
label_desc: Use image node_id 4 for calling a global function with example usage: test_extend() without return types