Summary implements Serializable { @Override public String toString() { Joiner joiner = Joiner.on(""); return joiner.join("mean:", Utils.roundUp(mean()), " stdev:", Utils.roundUp(stdev()), " var:", Utils.roundUp(variance()), " cNA:", mNACount, " count:", mCount, " min:", Utils.roundUp(min()), " max:", Utils.roundUp(max())); } Summary();  Summary(double[] numbers);  Summary(long mCount, double mMean, double mSS, long mNACount,
      double mMin, double mMax); Summary newSummary(Summary a); long count(); long NACount(); double mean(); double mSS(); boolean isNA(); void setNACount(long n); double min(); double max(); void addToNACount(long number); Summary merge(double number); Summary merge(double[] numbers); Summary merge(Summary other); double sum(); double variance(); double stdev(); @Override String toString();  }
@Test public void testToString() { assertTrue(a.toString().equals( "mean:2.0 stdev:1.0 var:1.0 cNA:0 count:3 min:1.0 max:3.0")); assertTrue(d.toString().equals( "mean:4.5 stdev:3.08 var:9.5 cNA:3 count:6 min:1.0 max:9.0")); }