code: def test_defaults(self) -> None:
      t = bt.jitter("foo", width=0.5)
      assert isinstance(t, Field)
      assert t.field == "foo"
      assert isinstance(t.transform, Jitter)
      assert t.transform.width == 0.5
      assert t.transform.mean == 0
      assert t.transform.distribution == "uniform"
      assert t.transform.range is None
  
imports: from __future__ import annotations
  import pytest
  from bokeh.core.property.vectorization import Expr, Field
  from bokeh.models import CategoricalColorMapper, CategoricalMarkerMapper, CategoricalPatternMapper, CumSum, Dodge, EqHistColorMapper, FactorRange, Jitter, LinearColorMapper, LogColorMapper, Stack
  from tests.support.util.api import verify_all
  import bokeh.transform
label_desc: Use image node_id 2 for calling the Test_jitter obj's underlying member method code with example usage: obj.test_defaults() without return types