type Constructor<T> = new (type: string) => T;
declare class GirafeSingleton {
    private static instances;
    private static initializingSingletons;
    constructor(type: string);
    static getInstance<T>(this: Constructor<T>): T;
    isNullOrUndefined(val: unknown): val is null | undefined;
    isNullOrUndefinedOrBlank(val: unknown): val is "" | null | undefined;
}
export default GirafeSingleton;