code: def test_walk_generation_loner_root_node(self):
      g = create_test_graph()
      biasedrw = BiasedRandomWalk(g)
  
      nodes = ["loner"]  # this node has no edges including itself
      n = 1
      length = 1
      seed = None
      p = 0.5
      q = 1.0
  
      subgraphs = biasedrw.run(
          nodes=nodes, n=n, p=p, q=q, length=length, seed=seed
      )
      assert len(subgraphs) == 1
      assert (
          len(subgraphs[0]) == 1
      )  # always 1 since only the root node can every be added to the walk
  
      n = 10
      length = 1
      subgraphs = biasedrw.run(
          nodes=nodes, n=n, p=p, q=q, length=length, seed=seed
      )
      assert len(subgraphs) == n
      for subgraph in subgraphs:
          assert (
              len(subgraph) == 1
          )  # always 1 since only the root node can ever be added to the walk
  
      n = 10
      length = 10
      subgraphs = biasedrw.run(
          nodes=nodes, n=n, p=p, q=q, length=length, seed=seed
      )
      assert len(subgraphs) == n
      for subgraph in subgraphs:
          assert len(subgraph) == 1
  
imports: import numpy
  import pandas
  import pytest
  import networkx
  from stellargraph.data.explorer import BiasedRandomWalk
  from stellargraph.core.graph import StellarGraph
  from ..test_utils.graphs import create_test_graph, example_graph_random
label_desc: Use image node_id 4 for calling the TestBiasedRandomWalk obj's underlying member method code with example usage: obj.test_walk_generation_loner_root_node() without return types