def test_meld(backend):
h1 = DHeap(backend, items = [x for x in xrange(0,300)])
h2 = DHeap(backend, items = [x for x in xrange(300,500)])
h3 = DHeap(backend, items = [x for x in xrange(500,700)])
h4 = DHeap(backend, items = [x for x in xrange(700,1000)])
h1.meld(h2)
h3.meld(h4)
h1.meld(h3)
assert sorted(x for x in h1) == [x for x in xrange(0,1000)]
remove_items_from_heap(h1)
