code: def test_generator_init():
      generator = PaddedGraphGenerator(graphs=graphs)
      assert len(generator.graphs) == len(graphs)
  
imports: from stellargraph.core.graph import *
  from stellargraph.mapper.padded_graph_generator import PaddedGraphGenerator, PaddedGraphSequence
  import numpy
  import pytest
  from ..test_utils.graphs import example_graph_random, example_graph, example_hin_1
label_desc: Use image node_id 2 for calling a global function with example usage: test_generator_init() without return types