export declare const hasOwnProperty: (v: PropertyKey) => boolean;
export declare const isArray: (arg: any) => arg is any[];
export declare const isUint8Array: (x: unknown) => x is Uint8Array;
export declare const isFunction: (f: any) => f is (...args: any[]) => any;
export declare const isObject: (x: unknown) => x is Record<string, any>;
export declare const isEmptyObject: (x: unknown) => x is Record<string, any>;
export declare const isUndefined: (x: unknown) => x is undefined;
export declare const isString: (x: unknown) => x is string;
export declare const isEmptyString: (x: unknown) => boolean;
export declare const isNull: (x: unknown) => x is null;
export declare const isNullish: (x: unknown) => x is null | undefined;
export declare const isDate: (x: unknown) => x is Date;
export declare const isNumber: (x: unknown) => x is number;
export declare const isBoolean: (x: unknown) => x is boolean;
export declare const isDocument: (x: unknown) => x is Document;
export declare const isFormData: (x: unknown) => x is FormData;
export declare const isFile: (x: unknown) => x is File;