fix robust
fix robust

drewokane/xray,cpaulik/xray,pydata/xarray,jhamman/xray,markelg/xray,jhamman/xarray,chunweiyuan/xarray,pydata/xarray,markelg/xray,jcmgray/xarray,cpaulik/xray,markelg/xray,shoyer/xarray,NicWayand/xray,xray/xray,shoyer/xray,shoyer/xarray,jhamman/xarray,rabernat/xray,petercable/xray,rabernat/xray,jhamman/xarray,pydata/xarray