s := 0
	for v := range r {
		n++
		s += v
	}
	if n != niter || s != expect {
		t.Errorf("Expected sum %d (got %d) from %d iter (saw %d)",
			expect, s, niter, n)
	}
}

func TestShrinkStackDuringBlockedSend(t *testing.T) {
	// make sure that channel operations still work when we are
	// blocked on a channel send and we shrink the stack.
	// NOTE: this test probably won't fail unless stack1.go:stackDebug