throw an error if provided element isn't an element
throw an error if provided element isn't an element

RobertoMalatesta/rickshaw,adeelshahid/rickshaw,dpobel/rickshaw,adeelshahid/rickshaw,toniher/rickshaw,shutterstock/rickshaw,mcanthony/rickshaw,shutterstock/rickshaw,zhangweiabc/rickshaw,IoTboy/rickshaw,JaySunSyn/rickshaw,IoTboy/rickshaw,dwt/rickshaw,egorovpavel/rickshaw,mcanthony/rickshaw,egorovpavel/rickshaw,IoTboy/rickshaw,JaySunSyn/rickshaw,butterflyhug/rickshaw,pombredanne/rickshaw,mcanthony/rickshaw,RobertoMalatesta/rickshaw,boomtrain/rickshaw,zhangweiabc/rickshaw,openhose/rickshaw,boomtrain/rickshaw,adeelshahid/rickshaw,pombredanne/rickshaw,pombredanne/rickshaw,shutterstock/rickshaw,butterflyhug/rickshaw,zhangweiabc/rickshaw,egorovpavel/rickshaw,openhose/rickshaw,openhose/rickshaw,boomtrain/rickshaw,dwt/rickshaw,toniher/rickshaw,dwt/rickshaw,dpobel/rickshaw,JaySunSyn/rickshaw,butterflyhug/rickshaw,dpobel/rickshaw,RobertoMalatesta/rickshaw,toniher/rickshaw