1. More factory methods for HM RealTimeQueues (fromArray(), fromStream()).
2. Rename the elem() method to contains in List.
More optimized version of notContains(). Avoid the virtual function call.
Use the method reference via object syntax instead of explicitly specifying a new lambda.  Perhaps this is more efficient.
1. Lots more functions for queues.
2. Introduce a Queue interface and teach HMRealTimeQueues to use it.