List all the nodes in a TF graph.
    tfgraph: A TF Graph object.
    tfgraphdef: A TF GraphDef object.

def dump_tf_graph(tfgraph, tfgraphdef):
    """List all the nodes in a TF graph.
    tfgraph: A TF Graph object.
    tfgraphdef: A TF GraphDef object.
    """
    print("Nodes ({})".format(len(tfgraphdef.node)))
    f = "{:15} {:59} {:20} {}"
    print(f.format("kind", "scopeName", "shape", "inputs"))
    for node in tfgraphdef.node:
        scopename = node.name
        kind = node.op
        inputs = node.input
        shape = tf.graph_util.tensor_shape_from_node_def_name(tfgraph, scopename)
        print(f.format(kind, scopename, str(shape), inputs))