Check friendship

OpenIMClient.getInstance().friendshipManager.checkFriend(
    new OnBase<List<FriendshipInfo>>() {
        @Override
        public void onSuccess(List<FriendshipInfo> relations) {
            showFriendshipStates(relations);
        }

        @Override
        public void onError(int code, String error) {
            recordFriendshipCheckFailure(code, error);
        }
    },
    Arrays.asList("user_a", "user_b")
);

The callback returns List<FriendshipInfo>. Each item's userID identifies the target user. result == 1 means the user is a friend and is not in the blacklist. Interpret other result values only through the server contract; do not create additional client-side states.

This method only establishes a relationship snapshot and does not trigger friendship callbacks. Use getFriendsInfo() when nickname, avatar, or friend remark data is required.