export declare function isClass(target: any): target is Function;
/**
 * getGlobalType
 * @param key class, string or symbol.
 * @param prefix the prefix of type.
 */
export declare function getGlobalType(key: any, prefix?: string): string | symbol;
export declare function isExtendOf(classType: Function, superClassType: Function): boolean;
export declare function symbolString(key: string | symbol): string;