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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 fire(self, tag, msg):
        '''
        This replaces a function in main called 'fire'

        It fires an event into the salt bus.
        '''
        if __opts__.get('__role') == 'master':
            fire_master = salt.utils.event.get_master_event(
                __opts__,
                __opts__['sock_dir']).fire_master
        else:
            fire_master = None

        if fire_master:
            fire_master(msg, tag)
        else:
            __salt__['event.send'](tag, msg)