code: def test_immutable_nodes(nodes, edges):
      # Expect nodes to remain immutable after any bundling operation
      original = nodes.copy()
      directly_connect_edges(nodes, edges)
      assert original.equals(nodes)
  
file_path: datashader/datashader/tests/test_bundling.py
imports: from __future__ import annotations
  import pytest
  import numpy
  import pandas
  from datashader.bundling import directly_connect_edges, hammer_bundle
  from datashader.layout import circular_layout, forceatlas2_layout, random_layout
label_desc: Use image node_id 4 for calling a global function with example usage: test_immutable_nodes(nodes, edges) without return types