def get_host_post_state(self):
        """Get the current state of system POST.

        Retrieves current state of system POST.

        :returns: POST state of the server. The valida states are:-
                  null, Unknown, Reset, PowerOff, InPost,
                  InPostDiscoveryComplete and FinishedPost.
        :raises: IloError, on an error from iLO
        """
        sushy_system = self._get_sushy_system(PROLIANT_SYSTEM_ID)
        return GET_POST_STATE_MAP.get(sushy_system.post_state)