function groupBy(items: Record<string, any>[], key: string): Record<string, Record<string, any>[]> {
  let group: Record<string, Record<string, any>[]> = {}
  items.forEach((v)=>{
    let gkey = v[key]
    if(!group[gkey]) group[gkey] = []
    group[gkey].push(v)
  })
  return group;
}

// No modificar: necesario para evaluar el resultado.
export { groupBy };