function createGridClipShape$1(rect, seriesModel, cb) {
    var rectEl = new Rect({
        shape: {
            x: rect.x - 10,
            y: rect.y - 10,
            width: 0,
            height: rect.height + 20
        }
    });
    initProps(rectEl, {
        shape: {
            width: rect.width + 20
        }
    }, seriesModel, cb);

    return rectEl;
}
Compute the x-position for each node.

Here we use Kahn algorithm to detect cycle when we traverse
the node to computer the initial x position.

@param {module:echarts/data/Graph~Node} nodes  node of sankey view
@param  {number} nodeWidth  the dx of the node
@param  {number} width  the whole width of the area to draw the view