export declare function init(options: {
    toggle?: Element | null;
    classes?: {
        dark: string;
        light: string;
    };
    default?: string;
    storageKey?: string;
    onInit?: (toggle?: Element | null) => unknown;
    onUserToggle?: (toggle?: Element | null) => unknown;
    onChange?: (theme: string, toggle?: Element | null) => unknown;
}): void;