Fill the Mor objects queue that will be asynchronously processed later.
        Resolve the vCenter `rootFolder` and initiate hosts and virtual machines
        discovery.

def _cache_morlist_raw(self, instance):
        """
        Fill the Mor objects queue that will be asynchronously processed later.
        Resolve the vCenter `rootFolder` and initiate hosts and virtual machines
        discovery.
        """
        i_key = self._instance_key(instance)
        self.log.debug("Caching the morlist for vcenter instance {}".format(i_key))

        # If the queue is not completely empty, don't do anything
        for resource_type in RESOURCE_TYPE_METRICS:
            if self.mor_objects_queue.contains(i_key) and self.mor_objects_queue.size(i_key, resource_type):
                last = self.cache_config.get_last(CacheConfig.Morlist, i_key)
                self.log.debug(
                    "Skipping morlist collection: the objects queue for the "
                    "resource type '{}' is still being processed "
                    "(latest refresh was {}s ago)".format(ensure_unicode(resource_type), time.time() - last)
                )
                return

        tags = ["vcenter_server:{}".format(ensure_unicode(instance.get('name')))]
        regexes = {
            'host_include': instance.get('host_include_only_regex'),
            'vm_include': instance.get('vm_include_only_regex'),
        }
        include_only_marked = is_affirmative(instance.get('include_only_marked', False))

        # Discover hosts and virtual machines
        server_instance = self._get_server_instance(instance)
        use_guest_hostname = is_affirmative(instance.get("use_guest_hostname", False))
        all_objs = self._get_all_objs(
            server_instance, regexes, include_only_marked, tags, use_guest_hostname=use_guest_hostname
        )

        self.mor_objects_queue.fill(i_key, dict(all_objs))
        self.cache_config.set_last(CacheConfig.Morlist, i_key, time.time())