Incorrect dynamic dataset visualization

[nulpoet]

I want to visualize a weighted dynamic graph.
I tried inputing following json file in the demo https://github.com/uskudnik/GraphGL/blob/master/dynamic-demos/java-dependencies.html.

{"nodes": {
    "1": "java.awt.MenuBar", 
    "2": "java.awt.peer.FramePeer", 
    "3": "java.awt.geom.NoninvertibleTransformException", 
    "4": "java.awt.geom.Point2D.Double"
    },
  "edges": [
    {"source":"1", "weight":2, "target":"2", "edgeid":null},
    {"source":"1", "weight":2, "target":"3", "edgeid":null},
    {"source":"1", "weight":8, "target":"4", "edgeid":null}
  ]
}

The result is not as expected considering there is a repulsive force between each pair of nodes
Ideally, this should yield a planar graph with nodes "2" & "3" on one side of the central node node "1" and "4" being on the other side.
Also, if it considers edge weights then distance between "1" & "4" smaller than "1" & "2" or "1" & "3".
So, what am I missing here?