Add random example

examples/random_node.py

+from random import Random
+
+from pydtn import Network, Node, random_trace, random_traffic
+
+class RandomNode(Node):
+    def __init__(self, seed=None, **options):
+        super().__init__(**options)
+        self.random = Random(seed)
+
+    def forward(self, packet):
+        neighbours = list(self.neighbours)
+        if neighbours:
+            target = self.random.choice(neighbours)
+            return {target: 'random'}
+        return {}
+
+def main():
+    nodes = 50
+    seed  = 42
+    traffic_speed = 1
+
+    node_options = {
+        'seed': seed,
+        'tick_rate': 1,
+    }
+
+    nodes = {
+        node_id: RandomNode(**node_options)
+        for node_id in range(nodes)
+    }
+
+    trace = random_trace(nodes, seed=seed)
+    traffic = random_traffic(nodes, speed=traffic_speed, seed=seed)
+    network = Network(nodes, traffic=traffic, trace=trace)
+
+    # run simulation for 500 ticks
+    network.run(until=500)
+
+    print(network.stats)
+
+if __name__ == '__main__':
+    exit(main())