method ArrayUtils.groupByimport { ArrayUtils } from "https://dotland.deno.dev/x/ts_morph@17.0.1/common/mod.ts"; groupBy<T>(items: ReadonlyArray<T>, getGroup: (item: T) => string | number): T[][]Type ParametersTParametersitems: ReadonlyArray<T>getGroup: (item: T) => string | numberReturnsT[][]