### Question:
TabixIndex implements GenotypeDataIndex { @Override public List<String> getSeqNames() { return Collections.unmodifiableList(Arrays.asList(seqNames)); } TabixIndex(File tabixIndexFile, File bzipFile, VariantLineMapper variantLineMapper); @Override List<String> getSeqNames(); TIndex[] getIndex(); @Override VariantQuery createQuery(); @Override RawLineQuery createRawLineQuery(); TabixIterator queryTabixIndex(String sequence, final int beg, final int end,
			BlockCompressedInputStream bzipInputStream);  }### Answer:
@Test public void getSeqNames() { List<String> seqNames = index.getSeqNames(); assertNotNull(seqNames); assertEquals(seqNames.size(), 3); assertEquals(seqNames.get(0), "1"); assertEquals(seqNames.get(1), "2"); assertEquals(seqNames.get(2), "3"); }