seq.addSequenceFeature(sf3);
// gene sub-type with right ID is valid
SequenceFeature sf4 = new SequenceFeature("snRNA_gene", "", 1, 2, 0f, null);
seq.addSequenceFeature(sf3);
// gene sub-type with right ID is valid
SequenceFeature sf4 = new SequenceFeature("snRNA_gene", "", 1, 2, 0f, null);