@Override
public BitCodec<SubstitutionVariation> buildCodec(CramHeader header,
CompressionHeader compression,
SequenceBaseProvider referenceBaseProvider,
DefaultMutableTreeNode parent) throws CramCompressionException {
SubstitutionVariationCodec substitutionCodec = new SubstitutionVariationCodec();
DefaultMutableTreeNode delNode = buildNode(substitutionCodec,
"Substitution codec");
parent.add(delNode);
substitutionCodec.baseChangeCodec = register(new BaseChangeCodec(),