import { ArrayHelper } from "./array-helper.class"; declare class MatrixHelper extends ArrayHelper { firstOrEmpty(input: ReadonlyArray): TItem[]; lastOrEmpty(input: ReadonlyArray): TItem[]; flatten(input: ReadonlyArray>): TItem[]; mapAndFlatten(input: ReadonlyArray, mapperFn: (inputItem: TInputItem) => ReadonlyArray): TResultItem[]; } export { MatrixHelper };