code: def test_expr_function() -> None:
      expr = CumSum(field="foo")
      transform = Dodge()
      assert bcpv.expr(expr) == bcpv.Expr(expr=expr)
      assert bcpv.expr(expr, transform) == bcpv.Expr(
          expr=expr, transform=transform
      )
      assert bcpv.expr(expr, transform=transform) == bcpv.Expr(
          expr=expr, transform=transform
      )
  
file_path: bokeh/tests/unit/bokeh/core/property/test_vectorization.py
imports: from __future__ import annotations
  import pytest
  from bokeh.models.expressions import CumSum
  from bokeh.models.transforms import Dodge
  from tests.support.util.api import verify_all
  import bokeh.core.property.vectorization
label_desc: Use image node_id 3 for calling a global function with example usage: test_expr_function() without return types