/// <reference types="koa__router" />
import { RouterContext } from '@koa/router';
import { InputBag as InputBagContract } from '@supercharge/contracts';
export declare class ResponseHeaderBag<ResponseHeaders> implements InputBagContract<ResponseHeaders> {
    /**
     * Stores the request headers as an object.
     */
    private readonly ctx;
    /**
     * Create a new instance.
     */
    constructor(ctx: RouterContext);
    /**
     * Returns the properties object of this input bag.
     */
    toJSON(): ResponseHeaders;
    /**
     * Returns all properties within this input bag or an object with all `keys` that exist in the bag.
     */
    all(): ResponseHeaders;
    all<R extends Record<string, any>>(): R;
    all<Key extends keyof ResponseHeaders>(...keys: Key[] | Key[][]): Partial<Record<keyof ResponseHeaders, ResponseHeaders[keyof ResponseHeaders]>>;
    /**
     * Returns the input value for the given `key`. Returns `undefined`
     * if the given `key` does not exist in the input bag.
     */
    get<Key extends keyof ResponseHeaders>(key: Key): ResponseHeaders[Key];
    get<Value = any, Key extends keyof ResponseHeaders = any>(key: Key, defaultValue: Value): ResponseHeaders[Key] | Value;
    get<Value = any>(key: string, defaultValue: Value): Value | undefined;
    /**
     * Set an input for the given `key` and assign the `value`. This
     * overrides a possibly existing input with the same `key`.
     */
    set<Key extends keyof ResponseHeaders>(key: Key, value: ResponseHeaders[Key]): this;
    set(values: Partial<ResponseHeaders>): this;
    set<Key extends keyof ResponseHeaders>(key: Key | Partial<ResponseHeaders>, value?: any): this;
    /**
     * Merge the given `data` object with the existing input bag.
     */
    merge(data: Partial<ResponseHeaders>): this;
    /**
     * Determine whether the given `input` is an object.
     */
    protected isObject(input: any): input is Record<string, any>;
    /**
     * Determine whether the input bag contains an item for the given `key`,
     * independently from the key’s assigned value. If you need to ensure
     * that a value is not `undefined`, use the related `has` method.
     */
    exists<Key extends keyof ResponseHeaders>(key: Key): boolean;
    /**
     * Determine whether an item with the given `key` exists in the input bag
     * and the assigned value is not `undefined`. The assigned value could
     * also be `null`. Empty states should explcitely use `undefinied`.
     */
    has<Key extends keyof ResponseHeaders>(key: Key): boolean;
    /**
     * Determine whether the input bag is missing a value for the given `key`.
     */
    isMissing<Key extends keyof ResponseHeaders>(key: Key): boolean;
    /**
     * Remove the input bag item for the given `key`.
     */
    remove<Key extends keyof ResponseHeaders>(key: Key): this;
    /**
     * Removes all data from the input bag.
     */
    clear(): this;
}