function findInAllWorkingSets(fullPath) {
        var index,
            result = [];

        _.forEach(_panes, function (pane) {
            index = pane.findInViewList(fullPath);
            if (index >= 0) {
                result.push({paneId: pane.id, index: index});
            }
        });

        return result;
    }
Finds all instances of the specified file in all working sets.
If there is a temporary view of the file, it is not part of the result set
@param {!string} fullPath - path of the file to find views of
@return {Array.<{pane:string, index:number}>} an array of paneId/index records