function chainimport { chain } from "https://deno.land/x/rambda@9.2.1/immutable.d.ts"; chain<T, U>(fn: (n: T) => readonly U[], list: readonly T[]): readonly U[]The method is also known as flatMap. chain<T, U>(fn: (n: T) => readonly U[]): (list: readonly T[]) => readonly U[]The method is also known as flatMap. Type ParametersTUParametersfn: (n: T) => readonly U[]list: readonly T[]Returnsreadonly U[]Type ParametersTUParametersfn: (n: T) => readonly U[]Returns(list: readonly T[]) => readonly U[]