added comment when returning length sequence
added comment when returning length sequence

Ensembl/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,dbolser-ebi/ensembl-variation,dbolser-ebi/ensembl-variation,dbolser/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,dbolser/ensembl-variation,dbolser-ebi/ensembl-variation,dbolser/ensembl-variation,dbolser/ensembl-variation,Ensembl/ensembl-variation