code: def test_nodemapper_constructor_no_feats():
      """
      GraphSAGENodeGenerator requires the graph to have features
      """
      n_feat = 4
  
      G = example_graph()
      with pytest.raises(RuntimeError):
          GraphSAGENodeGenerator(G, batch_size=2, num_samples=[2, 2])
  
imports: from stellargraph.core.graph import *
  from stellargraph.mapper import *
  import networkx
  import numpy
  import random
  import pytest
  import pandas
  import scipy.sparse
  from ..test_utils.graphs import example_graph, example_graph_random, example_hin_1, create_graph_features, repeated_features, weighted_tree
  from ..None import test_utils
label_desc: Use image node_id 5 for calling a global function with example usage: test_nodemapper_constructor_no_feats() without return types