/**
 * Event listener function
 */
export interface Listener {
    (...args: any[]): void;
    _?: this;
}
/**
 * Subset of node's [Emitter class](https://nodejs.org/api/events.html#events_class_eventemitter)
 *
 * @param logger Optional logger instance. Must comply to the [Console interface](https://developer.mozilla.org/es/docs/Web/API/Console).
 */
export declare class Emitter {
    logger: Console;
    events: Record<string, Listener[]>;
    constructor(logger?: Console);
    /**
     * Adds the listener function to the end of the listeners array for the event named eventName.
     *
     * @param eventName The name of the event.
     * @param listener Listener fn that handles the evt.
     * @returns The Emitter instance.
     */
    on(eventName: string, listener: Listener): this;
    /**
     * Removes the specified listener from the listener array for the event named eventName.
     *
     * @param eventName The name of the event.
     * @param listener Listener fn that handles the evt.
     * @returns The Emitter instance.
     */
    removeListener(eventName: string, listener: Listener): this;
    /**
     * Removes all listeners, or those of the specified eventName.
     *
     * @param eventName The name of the event. Optional if omitted all listeners will be removed.
     * @returns The Emitter instance.
     */
    removeAllListeners(eventName: string): this;
    /**
     * Adds a one time listener function for the event named eventName. The next time eventName is triggered,
     * this listener is removed and then invoked.
     *
     * @param eventName The name of the event.
     * @param listener Listener fn that handles the evt.
     * @returns The Emitter instance.
     */
    once(eventName: string, listener: Listener): this;
    /**
     * Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered,
     * passing the supplied arguments to each.
     *
     * @param eventName The name of the event.
     * @returns Returns true if the event had listeners, false otherwise.
     */
    emit(eventName: string, ...args: any[]): boolean;
}