code: function scaleSankeySize(graph, margin) {
  
      var maxColumn = max(graph.nodes, function (node) {
        return node.column;
      });
  
      var currentWidth = x1 - x0;
      var currentHeight = y1 - y0;
  
      var newWidth = currentWidth + margin.right + margin.left;
      var newHeight = currentHeight + margin.top + margin.bottom;
  
      var scaleX = currentWidth / newWidth;
      var scaleY = currentHeight / newHeight;
  
      x0 = x0 * scaleX + margin.left;
      x1 = margin.right == 0 ? x1 : x1 * scaleX;
      y0 = y0 * scaleY + margin.top;
      y1 = y1 * scaleY;
  
      graph.nodes.forEach(function (node) {
        node.x0 = x0 + node.column * ((x1 - x0 - dx) / maxColumn);
        node.x1 = node.x0 + dx;
      });
  
      return scaleY;
    }
docs: Update the x0, y0, x1 and y1 for the sankeyCircular, to allow space for any circular links