factor interval tree construction out into a separate method
factor interval tree construction out into a separate method

james-monkeyshines/ensembl,Ensembl/ensembl,Ensembl/ensembl,Ensembl/ensembl,james-monkeyshines/ensembl,james-monkeyshines/ensembl,james-monkeyshines/ensembl,Ensembl/ensembl