ORACLE 12C : Shared Pool and durations enhancement

Recently when diagnosing a memory issue on the shared pool ora-4031 (11.2.0.3.9) i discovered that the root cause was related to duration management. Although, we have a lot of free space on every sub-pool and no fragmentation some duration was saturated.Riyaj Shamsudeen described a similar problem in his blog  https://orainternals.wordpress.com/2009/08/06/ora-4031-and-shared-pool-duration/   so i will not discuss the problem i faced here. In this post i want to show some change that appeared in the 12c version that can reduce this type of problem.