Representing the network as a graph.

Is there any way besides parsing the json to work with the network as a graph?

``` julia
using MXNet
using LightGraphs
using JSON

net = @mx.chain mx.Variable(:data) =>
mx.Convolution(num_filter = 64, kernel = (3,3), pad = (1, 1), stride=(1,1)) =>
mx.LeakyReLU(act_type = :prelu) =>
mx.Convolution(num_filter = 128, kernel = (3,3), pad = (1, 1), stride=(1,1)) =>
mx.LeakyReLU(act_type = :prelu) =>
mx.Convolution(num_filter = 2, kernel = (3,3), pad = (1, 1), stride=(1,1)) =>
mx.LeakyReLU(act_type = :prelu) =>
mx.SoftmaxOutput(name=:softmax, multi_output=true)

js_net = JSON.parse(mx.to_json(net))
nodes = js_net["nodes"]
graph = DiGraph(length(nodes))
for (idx, node) in enumerate(nodes)
for edge in node["inputs"]
x, _ = edge
add_edge!(graph, x+1, idx)
end
end
```

I am using this right now to determine which parts of the network should be frozen.