关于EMGroup，“需要获取群详情”是什么意思？调用哪个方法获取群详情？？

/*!

 *  \~chinese

 *  获取群组详情

 *

 *  @param aGroupId              群组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 group info

 *

 *  @param aGroupId              Group id

 *  @param aIncludeMembersList   Whether get member list

 *  @param aSuccessBlock         The callback block of success

 *  @param aFailureBlock         The callback block of failure

 *

 */

- (void)asyncFetchGroupInfo:(NSString *)aGroupId

         includeMembersList:(BOOL)aIncludeMembersList

                    success:(void (^)(EMGroup *aGroup))aSuccessBlock

                    failure:(void (^)(EMError *aError))aFailureBlock;