message: Better z-index example
diff: @@ -46,7 +46,7 @@ renderer.on('overNode', e => {
  graph.setNodeAttribute(node, 'z', 1);
  }
  else {
  - graph.setNodeAttribute(node, 'color', '#ccc');
  + graph.setNodeAttribute(node, 'color', '#bbb');
  graph.setNodeAttribute(node, 'z', 0);
  }
  });
  @@ -58,7 +58,7 @@ renderer.on('overNode', e => {
  graph.setEdgeAttribute(edge, 'z', 1);
  }
  else {
  - graph.setEdgeAttribute(edge, 'hidden', true);
  + graph.setEdgeAttribute(edge, 'color', '#eee');
  graph.setEdgeAttribute(edge, 'z', 0);
  }
  });
  