ios聊天室人数是怎么算的呢？occupantsCount返回的有时候不对

/*!
 *  \~chinese
 *  获取聊天室详情
 *
 *  @param aChatroomId           聊天室ID
 *  @param aIncludeMembersList   是否获取成员列表
 *  @param aSuccessBlock         成功的回调
 *  @param aFailureBlock         失败的回调
 *
 *  \~english
 *  Fetch chatroom's specification
 *
 *  @param aChatroomId           Chatroom id
 *  @param aIncludeMembersList   Whether get member list
 *  @param aSuccessBlock         The callback block of success
 *  @param aFailureBlock         The callback block of failure
 *
 */
- (void)asyncFetchChatroomInfo:(NSString *)aChatroomId
            includeMembersList:(BOOL)aIncludeMembersList
                       success:(void (^)(EMChatroom *aChatroom))aSuccessBlock
                       failure:(void (^)(EMError *aError))aFailureBlock;
先获取聊天室详情。