     }
      circle.source {
        fill: #93C464;
      }
      circle.target {
        fill: #41A368;
      }
    </style>
  </head>
  <body>
    <div id="viz">
      <svg style="width:600px;height:600px;" ></svg>
    </div>
    <script>
      var PromiseWrapper = d => new Promise(resolve => d3.csv(d, p => resolve(p)));
      
      Promise
        .all([
          PromiseWrapper("../data/nodelist.csv"),
          PromiseWrapper("../data/edgelist.csv")
        ])
        .then(resolve => {
          crea