@@ -0,0 +1,1147 @@
+package hex;%0A%0Aimport static hex.ModelMetricsMultinomial.updateHits;%0Aimport org.junit.Assert;%0Aimport org.junit.BeforeClass;%0Aimport org.junit.Test;%0Aimport static water.TestUtil.stall_till_cloudsize;%0A%0Apublic class HitRatioTest %7B%0A%0A  @BeforeClass() public static void setup() %7B stall_till_cloudsize(1); %7D%0A%0A  @Test%0A  public void testHits() %7B%0A    long%5B%5D hits = new long%5B4%5D;%0A    int actual_label = 3; int%5B%5D pred_labels = %7B0,3,2,1%7D; updateHits(hits, actual_label, pred_labels);%0A    Assert.assertTrue(hits%5B0%5D == 0);%0A    Assert.assertTrue(hits%5B1%5D == 1);%0A    Assert.assertTrue(hits%5B2%5D == 1);%0A    Assert.assertTrue(hits%5B3%5D == 1);%0A    actual_label = 0; pred_labels = new int%5B%5D%7B1,2,3,0%7D; updateHits(hits, actual_label, pred_labels);%0A    Assert.assertTrue(hits%5B0%5D == 0+0);%0A    Assert.assertTrue(hits%5B1%5D == 1+0);%0A    Assert.assertTrue(hits%5B2%5D == 1+0);%0A    Assert.assertTrue(hits%5B3%5D == 1+1);%0A    actual_label = 1; pred_labels = new int%5B%5D%7B0,3,1,2%7D; updateHits(hits, actual_label, pred_labels);%0A    Assert.assertTrue(hits%5B0%5D == 0+0+0);%0A    Assert.assertTrue(hits%5B1%5D == 1+0+0);%0A    Assert.assertTrue(hits%5B2%5D == 1+0+1);%0A    Assert.assertTrue(hits%5B3%5D == 1+1+1);%0A  %7D%0A%0A%0A%7D%0A

Add JUnit for HitRatio raw computation logic.