export declare class IpcProxyError extends Error {
    constructor(message?: string | undefined);
}
export declare function isFunction(value: unknown): value is Function;
/**
 * Fix ContextIsolation
 * @param key original key
 * @returns
 */
export declare function getSubscriptionKey(key: string): string;
export declare const webViewCallbackKey: "__reactNativePostMessageCatCallback__";
export declare const webViewHelperKey: "PostMessageCat";