function ruleSorter(a, b)
    {
        var result = WebInspector.AuditRule.SeverityOrder[a.severity || 0] - WebInspector.AuditRule.SeverityOrder[b.severity || 0];
        if (!result)
            result = (a.value || "").localeCompare(b.value || "");
        return result;
    }
@constructor
@extends {WebInspector.SidebarPane}
@param {!WebInspector.AuditCategoryResult} categoryResult