import { Promised } from "./utils";
declare global {
    interface Generator<T = unknown, TReturn = any, TNext = unknown> {
        /**
         * Appends a value to the end of the sequence.
         * @param item The value to append to source.
         * @returns A new sequence that ends with element.
         */
        append<TItem>(item: TItem): Generator<T | TItem, TNext, TReturn>;
    }
    interface AsyncGenerator<T = unknown, TReturn = any, TNext = unknown> {
        /**
         * Appends a value to the end of the sequence.
         * @param item The value to append to source.
         * @returns A new sequence that ends with element.
         */
        append<TItem>(item: Promised<TItem>): AsyncGenerator<T | TItem, TNext, TReturn>;
    }
}