class_docstr: Tests of Node2VecLinkGenerator class
code: def test_Node2VecLinkGenerator_1(self):
      G = example_graph()
      data_size = G.number_of_edges()
      edge_labels = [0] * data_size
  
      mapper = Node2VecLinkGenerator(
          G, batch_size=self.batch_size
      ).flow(G.edges(), edge_labels)
  
      assert len(mapper) == 2
  
      for batch in range(len(mapper)):
          nf, nl = mapper[batch]
          assert len(nf) == 2
          assert nf[0].shape == (min(self.batch_size, data_size),)
          assert nf[1].shape == (min(self.batch_size, data_size),)
          assert len(nl) == min(self.batch_size, data_size)
          assert all(nl == 0)
  
      with pytest.raises(IndexError):
          nf, nl = mapper[2]
  
imports: import numpy
  import networkx
  import pytest
  import random
  from stellargraph.mapper import *
  from stellargraph.core.graph import *
  from stellargraph.data.unsupervised_sampler import *
  from ..test_utils.graphs import example_graph, example_graph_random, example_hin_1, repeated_features, weighted_tree
  from ..None import test_utils
label_desc: Use image node_id 2 for calling the Test_Node2VecLinkGenerator obj's underlying member method code with example usage: obj.test_Node2VecLinkGenerator_1() without return types