sergeyDoroshenko

Every call of `Add` is followed with `FixHeight`. `FixHeight` has O(N) complexity because `FixHeight` is a BFS traversal.

Here is the exception content: [Content] Description: An assembly (probably "CSharp.DataStructures") must be rewritten using the code contracts binary rewriter (CCRewrite) because it is calling Contract.Requires and the CONTRACTS_FULL symbol...