import { PluginExtension } from './PluginExtension';
export declare class ExtensionManager {
    private static instance;
    private extensions;
    static getInstance(): ExtensionManager;
    static destroy(): void;
    registerExtension(extension: PluginExtension): void;
    getExtensions(): PluginExtension[];
    private clear;
}
export declare function registerPluginExtension(extension: PluginExtension): void;