Report container count per state

def _report_container_count(self, containers_by_id):
        """Report container count per state"""
        m_func = FUNC_MAP[GAUGE][self.use_histogram]

        per_state_count = defaultdict(int)

        filterlambda = lambda ctr: not self._is_container_excluded(ctr)
        containers = list(filter(filterlambda, containers_by_id.values()))

        for ctr in containers:
            per_state_count[ctr.get('State', '')] += 1

        for state in per_state_count:
            if state:
                m_func(self, 'docker.container.count', per_state_count[state], tags=['container_state:%s' % state.lower()])