Nice to see somebody else use a railway analogy. I like to use railways to describe why interfaces and encapsulation are important engineering principles. The t

Nice to see somebody else use a railway analogy. I like to use railways to describe why interfaces and encapsulation are important engineering principles. The track gauge is the interface between the people that build the railway and the people that build the trains. As long as they both implement the interface then together they get something much greater than the sum of its parts.