anchor.diff:              "label": "knows",
               "type": "edge",
               "outV": 1,
  -            "hiddens": {},
               "properties": {
                   "weight": 0.5
               }
  
positive.code:                 "label": "knows",
                  "type": "edge",
                  "outV": 1,
                  "hiddens": {
                      "@class": "java.util.HashMap"
                  },
                  "properties": {
                      "@class": "java.util.HashMap",
                      "weight": [
  
negative.code:             {
                  "id": 1,
                  "label": "age",
                  "value": 29,
                  "properties": {}
              }
  