code: def test_flow_node_ids(barbell):
      sample_points = np.linspace(0, 100, 25)
      generator = GraphWaveGenerator(
          barbell, scales=(0.1, 2, 3, 4), degree=10
      )
  
      node_ids = list(barbell.nodes())[:4]
  
      expected_targets = generator._node_lookup(node_ids)
      actual_targets = []
      for x in generator.flow(
          node_ids,
          sample_points=sample_points,
          batch_size=1,
          targets=expected_targets,
      ):
          actual_targets.append(x[1].numpy())
  
      assert all(
          a == b for a, b in zip(expected_targets, actual_targets)
      )
  
file_path: stellargraph/tests/mapper/test_graphwave_generator.py
imports: from stellargraph.core.graph import *
  from stellargraph.mapper.graphwave_generator import GraphWaveGenerator, _empirical_characteristic_function
  from ..test_utils.graphs import barbell
  import numpy
  import pytest
  import scipy.sparse
  import tensorflow
label_desc: Use image node_id 11 for calling a global function with example usage: test_flow_node_ids(barbell) without return types