interface FastIterator implements Iterator<T>import { type FastIterator } from "https://deno.land/x/rimbu@0.13.1/stream/main/fast-iterator.ts"; An iterator that extends the default Iterator interface with methods that give more performance. Type ParametersTMethodsfastNext(): T | undefinedReturns the next iterator value, or the given otherwise OptLazy value instead. fastNext<O>(otherwise: OptLazy<O>): T | Onext(): IteratorResult<T>Returns the next IteratorResult.