code: def major_complex(network, state):
      
      log.info('Calculating major complex...')
  
      result = complexes(network, state)
      if result:
          result = max(result)
      else:
          empty_subsystem = Subsystem(network, state, ())
          result = _null_sia(empty_subsystem)
  
      log.info("Finished calculating major complex.")
  
      return result
docs: Return the major complex of the network.
  
      Args:
          network (Network): The |Network| of interest.
          state (tuple[int]): The state of the network (a binary tuple).
  
      Returns:
          SystemIrreducibilityAnalysis: The |SIA| for the |Subsystem| with
          maximal |big_phi|.