Move extend_features() into the parent class
Move extend_features() into the parent class
BjornFJohansson/giraffe,addgene/giraffe,UndeadBlow/giraffe,BjornFJohansson/giraffe,UndeadBlow/giraffe,BjornFJohansson/giraffe,addgene/giraffe,addgene/giraffe,BjornFJohansson/giraffe,addgene/giraffe,BjornFJohansson/giraffe