code: def nodes():
      # Four nodes arranged at the corners of a 200x200 square with one node
      # at the center
      nodes_df = pd.DataFrame(
          {
              "id": np.arange(5),
              "x": [0.0, -100.0, 100.0, -100.0, 100.0],
              "y": [0.0, 100.0, 100.0, -100.0, -100.0],
          }
      )
      nodes_df.set_index("id")
      return nodes_df
  
file_path: datashader/datashader/tests/benchmarks/test_bundling.py
imports: 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 1 for calling a global function with example usage: nodes() and returns: nodes_df