__contains__(self, cid) (15 pts) Finds a ContentItem from the list by id, moving the ContentItem to the front of the list if found. This is the special method for the in operator to allow the syntax cid in object. Input int cid The id to search for in the CacheList Output bool True if the matching ContentItem is in the list, False otherwise

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?