public function testCompare()
 {
     $q = new MinPriorityQueue();
     $this->assertEquals(0, $q->compare(1, 1));
     $this->assertEquals(-1, $q->compare(1, 0));
     $this->assertEquals(1, $q->compare(0, 1));
 }
 /**
  * Try to enforce the eviction.
  * @todo Locking mechanism, so that a subsequent push() for the same key won't set the prio to a higher value
  * @param $offset
  */
 private function markForEviction($offset)
 {
     $this->queue->insert($offset, 0);
     $this->priority->offsetSet($offset, 0);
 }