nodes.json

{
  "root":{
    "color":"green",
    "next": ["node1","node2","node3"]
  },
  "node1":{
    "color":"red",
    "next":[]
  },
  "node2":{
    "color":"green",
    "next":["node4"]
  },
  "node3":{
    "color":"red",
    "next":[]
  },
  "node4":{
    "color":"red",
    "next":[]
  }
}