Add method to check is content is in another collection
Add method to check is content is in another collection


Former-commit-id: b5590a20f5a01e0fbe3aa4a856e6450a12d5cf8f
Former-commit-id: 7c42e5bbf445bfffb43de66ed823417c51d6e4df
Former-commit-id: 2675c6ef54e4d1ad9118400029a8ead243f426e9
ONSdigital/florence,ONSdigital/florence,ONSdigital/florence,ONSdigital/florence