@Test(expectedExceptions = IllegalArgumentException.class)
 public void testAllNull() throws Exception {
   final Map<String, PerReadAlleleLikelihoodMap> perReadAlleleLikelihoodMap = null;
   final VariantContext vc = null;
   final ReferenceContext referenceContext = null;
   final InfoFieldAnnotation cov = new RMSMappingQuality();
   final Map<String, Object> annotate =
       cov.annotate(referenceContext, vc, perReadAlleleLikelihoodMap); // vc can't be null
 }
  @Test
  public void testNullStratifiedPerReadAlleleLikelihoodMap() throws Exception {
    final Map<String, PerReadAlleleLikelihoodMap> perReadAlleleLikelihoodMap = null;
    final VariantContext vc = makeVC();
    final ReferenceContext referenceContext = null;
    final InfoFieldAnnotation cov = new RMSMappingQuality();
    final Map<String, Object> annotate =
        cov.annotate(referenceContext, vc, perReadAlleleLikelihoodMap);
    Assert.assertNull(annotate);

    Assert.assertEquals(cov.getDescriptions().size(), 1);
    Assert.assertEquals(cov.getDescriptions().get(0).getID(), VCFConstants.RMS_MAPPING_QUALITY_KEY);
  }
 @Test
 public void testDescriptions() throws Exception {
   final InfoFieldAnnotation cov = new RMSMappingQuality();
   Assert.assertEquals(cov.getDescriptions().size(), 1);
   Assert.assertEquals(cov.getDescriptions().get(0).getID(), VCFConstants.RMS_MAPPING_QUALITY_KEY);
 }