code: def test_object_setitem_delegated():
      """Delegation in __setitem__ works"""
  
      class ThingDelegate:
          def __init__(self, value):
              self.value = value
  
      class Thing(Object):
          _delegated_properties = ["value"]
  
          def __init__(self, value=None, **data):
              self._delegate = ThingDelegate(value)
              super().__init__(**data)
  
      thing = Thing()
      assert thing["value"] is None
      with pytest.warns(FionaDeprecationWarning, match="immutable"):
          thing["value"] = 1
      assert thing["value"] == 1
  
imports: import pytest
  from fiona.errors import FionaDeprecationWarning
  from fiona.model import _Geometry, Feature, Geometry, Object, ObjectEncoder, Properties, decode_object
label_desc: Use image node_id 7 for calling a global function with example usage: test_object_setitem_delegated() without return types