Clean up collection class
Clean up collection class

iinux/Slim,akrabat/Slim,slimphp/Slim,AndrewCarterUK/Slim,designermonkey/Slim,RealSelf/Slim,feryardiant/slim,Sam-Burns/Slim,juliangut/Slim,foxyantho/Slim,mnapoli/Slim,opengeek/Slim,iinux/Slim,JoeBengalen/Slim,dopesong/Slim,iinux/Slim,somjit2514/basic,samsonasik/Slim,jaapverloop/Slim