import type { PluginConstructor } from '@jbrowse/core/Plugin';
import type { LoadedPlugin } from '@jbrowse/core/PluginLoader';
export declare function initializeWorker(corePlugins: PluginConstructor[], opts: {
    fetchESM?: (url: string) => Promise<LoadedPlugin>;
    fetchCJS?: (url: string) => Promise<LoadedPlugin>;
}): Promise<void>;