/** A helper class to spread the event to additional event handlers added from external sources. */
export declare class EventHandler<Type> {
    private callbacks;
    /** Returns the added callback on success or null, if something went wrong. */
    add<Callback extends (arg: Type) => void>(callback: Callback): Callback | null;
    /** Returns true if the input callback has been found and removed and false if not. */
    remove<Callback extends (arg: Type) => void>(callback: Callback): boolean;
    constructor();
    /** Emits the event-data for each of the existing handlers. */
    static Emit<Type>(handler: EventHandler<Type>, event: Type): void;
}