AbhinavAnnam/FlowRider ? reverse-engineered prompt

Build me a small Python app that simulates network traffic over a topology.

I want to be able to define a network of nodes and connections, then run a traffic simulation that sends flows through it and shows what is happening as it runs. Please make it easy to edit the topology, start the simulation from a main script, and see clear output in the terminal about the routes, traffic levels, and any congestion or bottlenecks.

If it makes sense, keep the code split into a simple topology file, a traffic engine file, and a main entry point. Add a few example nodes and flows so I can run it right away and see it work. Keep it lightweight and readable, and look up current Python best practices if you need to.