Number of members in the supergroup or channel; 0 if unknown. Currently, it is guaranteed to be known only if the supergroup or channel was received through Client.get_chat_similar_chats Client.get_chats_to_post_stories Client.get_created_public_chats Client.get_groups_in_common Client.get_inactive_supergroup_chats Client.get_recommended_chats Client.get_suitable_discussion_chats Client.get_user_privacy_setting_rules Client.get_video_chat_available_participants Client.search_public_chats or in chatFolderInviteLinkInfo.missing_chat_ids, or in userFullInfo.personal_chat_id, or for chats with messages or stories from publicForwards and foundStories