test PriorityQueue.

Signed-off-by: Flycoding <Flycoding@yeah.net>
test java.util.Collections.singleton(String).

Signed-off-by: Flycoding <Flycoding@yeah.net>
test java.util.Collections.binarySearch(List<? extends Comparable<?
super Integer>>, Integer).

Signed-off-by: Flycoding <Flycoding@yeah.net>