public OutputStream scaleThroughput(double v) {
        return new OutputStream(id, rate.scaleBy(v), areKeysSkewed);
    }
@Test
    public void scaleThroughput() {
        OutputStream orig = new OutputStream("ID", new NormalDistStats(100.0, 1.0, 99.0, 101.0), false);
        OutputStream scaled = orig.scaleThroughput(2.0);
        assertEquals(orig.id, scaled.id);
        assertEquals(orig.areKeysSkewed, scaled.areKeysSkewed);
        assertEquals(scaled.rate.mean, 200.0, 0.0001);
        assertEquals(scaled.rate.stddev, 1.0, 0.0001);
        assertEquals(scaled.rate.min, 199.0, 0.0001);
        assertEquals(scaled.rate.max, 201.0, 0.0001);
    }