code: def test_limits():
      area_was = resource.limits["area"]  # Save state.
      area_expected = area_was - 100
      resource.limits["area"] = area_expected
      assert resource.limits["area"] <= area_expected
      # We have no images loaded, so the current area should be zero.
      assert resource.limits.resource("area") == 0
      del resource.limits["area"]
      assert resource.limits["area"] == 0
      resource.limits["area"] = area_was  # To restore for other tests.
      # Non functional smoke test.
      for _ in resource.limits:
          pass
      assert len(resource.limits) > 0
  
file_path: wand/tests/_resource_test.py
imports: from pytest import mark
  from wand import exceptions, resource
label_desc: Use image node_id 2 for calling a global function with example usage: test_limits() without return types