{
    "nodes":[
      {"name":"a","width":60,"height":40},
      {"name":"b","width":60,"height":40},
      {"name":"c","width":60,"height":40},
      {"name":"d","width":60,"height":40},
      {"name":"e","width":60,"height":40},
      {"name":"f","width":60,"height":40},
      {"name":"g","width":60,"height":40}
    ],
    "links":[
      {"source":1,"target":2},
      {"source":2,"target":3},
      {"source":3,"target":4},
      {"source":0,"target":1},
      {"source":2,"target":0},
      {"source":3,"target":5},
      {"source":0,"target":5}
    ],
	"groups":[
	  {"leaves":[0], "groups":[1]},
	  {"leaves":[1,2]},
	  {"leaves":[3,4]}
	]
}