Report volume count per state (dangling or not)

def _report_volume_count(self):
        """Report volume count per state (dangling or not)"""
        m_func = FUNC_MAP[GAUGE][self.use_histogram]

        attached_volumes = self.docker_util.client.volumes(filters={'dangling': False})
        dangling_volumes = self.docker_util.client.volumes(filters={'dangling': True})
        attached_count = len(attached_volumes.get('Volumes', []) or [])
        dangling_count = len(dangling_volumes.get('Volumes', []) or [])
        m_func(self, 'docker.volume.count', attached_count, tags=['volume_state:attached'])
        m_func(self, 'docker.volume.count', dangling_count, tags=['volume_state:dangling'])