q2) -> Double.compare( ((double) q2.priority) / sumOfPrioritiesByGroup.get(getTenantAndGroupIdentifier(q2)), ((double) q1.priority) / sumOfPrioritiesByGroup.get(getTenantAndGroupIdentifier(q1)));
q2) -> Double.compare( ((double) q2.priority) / sumOfPrioritiesByGroup.get(getTenantAndGroupIdentifier(q2)), ((double) q1.priority) / sumOfPrioritiesByGroup.get(getTenantAndGroupIdentifier(q1)));