@Override
    public boolean containsFreeSlot(AllocationID allocationId) {
        return freeSlots.contains(allocationId);
    }
@Test
    void testContainsFreeSlotReturnsFalseIfSlotDoesNotExist() {
        final DefaultAllocatedSlotPool slotPool = new DefaultAllocatedSlotPool();

        assertThat(slotPool.containsFreeSlot(new AllocationID())).isFalse();
    }