text: var diagram = SVG('drawing').viewbox(0, 0, 100, 100);
  
  function draw(AST){
    // initialize SVG.js
    var columns = AST.actors.length;
    var column_margin_width = (100/columns)*0.1;
    var column_width = (100-((columns-1)*column_margin_width))/columns;
    var total_column_width = column_width + column_margin_width;
  
    AST.actors.forEach(function(actor, index){
      diagram.rect(column_width, 30).move(total_column_width*index, 0).fill('#f06');
    });
  }
  
  var ast = {
    title: 'Test SVG',
    actors: [{name:'lb', label:'LB'},{name:'proxy', label:'Proxy'},{name:'test', label:'Test'}],
    lb: {},
    proxy: {},
    test: {},
  }
  
  draw( ast );
  
  function download(){
    var svgData = diagram.svg();
    var svgBlob = new Blob([svgData], {type:"image/svg+xml;charset=utf-8"});
    var svgUrl = URL.createObjectURL(svgBlob);
    var downloadLink = document.getElementById("download");
    downloadLink.href = svgUrl;
    downloadLink.download = ast.title+".svg";
  }
  