/**
 * Node storage
 * Please take care of the persistence with source property
 */
export declare class NodeStorage {
    /**
     * Storage source
     */
    source: [string, string][];
    /**
     * Constructor
     */
    constructor();
    /**
     * Returns the number of key/value pairs currently present in the list
     */
    get length(): number;
    /**
     * Empties the list associated with the object of all key/value pairs, if there are any.
     */
    clear(): void;
    /**
     * Returns the current value associated with the given key, or null if the given key does not exist in the list
     * @param key Key
     */
    getItem(key: string): string | null;
    /**
     * Returns the name of the nth key in the list, or null if n is greater than or equal to the number of key/value pairs in the object.
     */
    key(index: number): string | null;
    /**
     * Removes the key/value pair with the given key from the list associated with the object, if a key/value pair with the given key exists.
     */
    removeItem(key: string): void;
    /**
     * Sets the value of the pair identified by key to value, creating a new key/value pair if none existed for key previously.
     *
     * Throws a "QuotaExceededError" DOMException exception if the new value couldn't be set. (Setting could fail if, e.g., the user has disabled storage for the site, or if the quota has been exceeded.)
     */
    setItem(key: string, value: string): void;
}