parse empty string sort key from query string as null
parse empty string sort key from query string as null

arokem/AFQ-Browser,yeatmanlab/AFQ-viz,yeatmanlab/AFQ-Browser,yeatmanlab/AFQ-Browser,richford/AFQ-Browser,yeatmanlab/AFQ-Browser,arokem/AFQ-Browser,richford/AFQ-Browser,richford/AFQ-viz,yeatmanlab/AFQ-viz,richford/AFQ-viz,richford/AFQ-Browser,arokem/AFQ-Browser