/**
 * Mixins are a way of extending classes with additional functionality.
 * For more info: https://www.typescriptlang.org/docs/handbook/mixins.html#alternative-pattern
 */
/**
 * Copies the methods from the mixin class to the base class.
 * The constructor is not copied. It has to be called using 'extend'.
 */
export declare function extendClass(baseClass: any, mixinClasses: any[]): void;
export declare function extendConstructor(baseClass: any, mixinClass: any, ...constructorArgs: any[]): any;
/**
 * We use '_constructor' instead of 'constructor' because
 * you can't call a class's constructor without the 'new' keyword.
 * But we don't want to use 'new' because we want to modify an existing object.
 */
export interface Mixin {
    _constructor?(): any;
}
export interface Destroyable {
    destroy$: any;
}