code: def node_compat(g1, g2, v1, v2):
      """Node compatibility function for isomorphism tests"""
      return g1.vs[v1]["color"] == g2.vs[v2]["color"]
  
imports: import unittest
  from random import shuffle
  from igraph import Graph
label_desc: Use image node_id 1 for calling a global function with example usage: node_compat(g1, g2, v1, v2) and returns: unknown