def causal_nexus(network, before_state, after_state,
                 direction=Direction.BIDIRECTIONAL):
    """Return the causal nexus of the network."""
    validate.is_network(network)

    log.info("Calculating causal nexus...")
    result = nexus(network, before_state, after_state, direction)
    if result:
        result = max(result)
    else:
        null_transition = Transition(
            network, before_state, after_state, (), ())
        result = _null_ac_sia(null_transition, direction)

    log.info("Finished calculating causal nexus.")
    log.debug("RESULT: \n%s", result)
    return result
def causal_nexus ( network , before_state , after_state , direction = Direction . BIDIRECTIONAL ) : validate . is_network ( network ) log . info ( "Calculating causal nexus..." ) result = nexus ( network , before_state , after_state , direction ) if result : result = max ( result ) else : null_transition = Transition ( network , before_state , after_state , ( ) , ( ) ) result = _null_ac_sia ( null_transition , direction ) log . info ( "Finished calculating causal nexus." ) log . debug ( "RESULT: \n%s" , result ) return result
Return the causal nexus of the network.