The Bridgekeeper asks the iterator one final question: “Are you done?”
{ done: false }
“How about now?”
{ done: false }
“Now?”
{ done: false }
It’s a generator. It yields values on demand, pauses between calls, and resumes exactly where it left off. It’s never done until someone stops asking — or until the data runs out, whichever comes first.
The Bridgekeeper, having learned that some questions have no final answer, steps aside. The iterator crosses the bridge, yielding as it goes.