code: def test_param_updates(transformer):
      with alt.data_transformers.enable(transformer):
          source = data.cars()
          size_param = alt.param(
              name="size",
              value=10,
              bind=alt.binding_range(min=1, max=100),
          )
          chart = (
              alt.Chart(source)
              .mark_point()
              .encode(
                  x="Horsepower:Q",
                  y="Miles_per_Gallon:Q",
                  size=size_param,
              )
              .add_params(size_param)
          )
  
          widget = alt.JupyterChart(chart)
  
          # There should be one param and zero selections
          assert len(widget.selections.trait_values()) == 0
          assert len(widget.params.trait_values()) == 1
  
          # Initial value should match what was provided
          assert widget.params.size == 10
  
          # Update param from python
          widget.params.size = 50
          assert widget.params.size == 50
  
file_path: altair/tests/test_jupyter_chart.py
imports: import altair
  from altair.jupyter.jupyter_chart import IntervalSelection, IndexSelection, PointSelection
  from vega_datasets import data
  import pandas
  import pytest
label_desc: Use image node_id 5 for calling a global function with example usage: test_param_updates(transformer) without return types