code: def run_doctests():
      import igraph
  
      num_failed = 0
      modules = [
          igraph,
          igraph.clustering,
          igraph.cut,
          igraph.datatypes,
          igraph.drawing.utils,
          igraph.formula,
          igraph.statistics,
          igraph.utils,
      ]
      for module in modules:
          num_failed += doctest.testmod(module)[0]
      return num_failed == 0
  
label_desc: Use image node_id 1 for calling a global function with example usage: run_doctests() and returns: unknown