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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def major_complex(network, state):
 """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|. """

    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