public void TestCombineMajority()
 {
     CollectionAssert.AreEqual(Empty, CombineAnnotationColumns.Majority(None));
     CollectionAssert.AreEqual(new [] { "a" }, CombineAnnotationColumns.Majority(Some));
     CollectionAssert.AreEqual(new [] { "a" }, CombineAnnotationColumns.Majority(Full));
     CollectionAssert.AreEqual(Empty, CombineAnnotationColumns.Majority(ManyEmpty));
 }