### Question:
VariantMerger { protected void validateAlternate(AlternateCoordinate alt) { if (alt.getChromosome() == null) { throw new IllegalStateException("Chromosome of alt is null: " + alt); } if (alt.getStart() == null) { throw new IllegalStateException("Start of alt is null: " + alt); } if (alt.getEnd() == null) { throw new IllegalStateException("End of alt is null: " + alt); } if (alt.getReference() == null) { throw new IllegalStateException("Reference of alt is null: " + alt); } if (alt.getAlternate() == null) { throw new IllegalStateException("Alternate of alt is null: " + alt); } } VariantMerger();  VariantMerger(boolean collapseDeletions); void setStudyId(String studyId); VariantMerger setExpectedFormats(List<String> formats); void addExpectedSamples(Collection<String> sampleNames); void setExpectedSamples(Collection<String> sampleNames); Set<String> getExpectedSamples(); String getGtKey(); void setGtKey(String gtKey); boolean updateDefaultKeys(String from, String to); String getDefaultValue(String key); String getDefaultValue(String key, String valueIfNull); void setDefaultValue(String key, String value); String getFilterKey(); void setFilterKey(String filterKey); String getAnnotationFilterKey(); void setAnnotationFilterKey(String annotationFilterKey); VariantMerger configure(VCFHeader header); VariantMerger configure(Collection<? extends VCFHeaderLine> lines); VariantMerger configure(VCFCompoundHeaderLine line); VariantMerger configure(String key, VCFHeaderLineCount number, VCFHeaderLineType type); VariantMerger configure(VariantFileHeader header); Variant mergeNew(Variant template, Collection<Variant> load); Variant createFromTemplate(Variant target); Variant merge(Variant current, Variant load); Variant merge(Variant current, Collection<Variant> load); static boolean isDeletion(AlternateCoordinate alt); static boolean isDeletion(VariantType type, Integer start, Integer end); static boolean isInsertion(AlternateCoordinate alt); static boolean isInsertion(VariantType type, Integer start, Integer end); Variant merge(Variant current, List<Pair<Variant, List<AlternateCoordinate>>> vatToAlts); static boolean hasAnyOverlap(Variant current, Variant other); static boolean hasAnyOverlap(Variant current, Variant other, Collection<AlternateCoordinate> alts); List<AlternateCoordinate> buildAltList(Variant variant); static AlternateCoordinate getMainAlternate(Variant variant); static boolean isSameVariant(Variant a, AlternateCoordinate b); static boolean isSameVariant(AlternateCoordinate a, AlternateCoordinate b); @Deprecated
    static final String VCF_FILTER; static final String GENOTYPE_FILTER_KEY; static final String GT_KEY; static final String PASS_VALUE; static final String DEFAULT_FILTER_VALUE; static final String DEFAULT_MISSING_GT; }### Answer:
@Test public void testValidateEmptyFields() { thrown.expect(IllegalStateException.class); Variant v = new Variant("1:1050:CTTTC:-"); AlternateCoordinate a1 = new AlternateCoordinate(null, 1050, null, "C", "T", VariantType.SNV); variantMerger.validateAlternate(a1); }