refactored extract tests based on code review
refactored extract tests based on code review

-used let
-used doubles
-added addtional tests

NikitaAvvakumov/osra,razorcd/osra,b264/osra,evo2013/osra,AgileVentures/osra,NikitaAvvakumov/osra,motasem-salem/osra,ZmagoD/osra,SergiosLen/osra,SergiosLen/osra,razorcd/osra,ZmagoD/osra,evo2013/osra,jmorcate/osra,robbiejackson/osra,b264/osra,razorcd/osra,gmunumel/osra,jmorcate/osra,jmorcate/osra,PurityControl/osra,NikitaAvvakumov/osra,gmunumel/osra,ZmagoD/osra,AgileVentures/osra,AgileVentures/osra,gmunumel/osra,guangfanxu/osra,b264/osra,robbiejackson/osra,guangfanxu/osra,robbiejackson/osra,SergiosLen/osra,motasem-salem/osra,motasem-salem/osra,PurityControl/osra,PurityControl/osra,guangfanxu/osra