final AlignmentI topAlignment = topViewport.getAlignment();
final AlignmentI bottomAlignment = bottomViewport.getAlignment();
AlignmentViewport cdna = topAlignment.isNucleotide() ? topViewport
final AlignmentI topAlignment = topViewport.getAlignment();
final AlignmentI bottomAlignment = bottomViewport.getAlignment();
AlignmentViewport cdna = topAlignment.isNucleotide() ? topViewport