       yOffset: 5
      }
    }
  ]);

  setInterval(function() {
    networkGraph.signal({
        from: 'a',
        to: 'b',
        color: getRandomColor(),
        duration: 1000,
        size: getRandomInt(3, 5)
      });
    
    networkGraph.signal({
        from: 'b',
        to: 'c',
        color: getRandomColor(),
        duration: 25000,
        size: getRandomInt(3, 5)
      });

    networkGraph.signal({
        from: 'c',
        to: 'd',
        color: getRandomColor(),
        duration: 80