export declare type Verifier<T> = (value: T | undefined) => boolean;
export declare const isUndefined: Verifier<unknown>;
export declare const isNotUndefined: Verifier<unknown>;
export declare const startsWith: (test: string) => Verifier<string>;
export declare const endsWith: (test: string) => Verifier<string>;
export declare const isLessThan: (min: number) => Verifier<number>;
export declare const isBetween: (min: number, max: number) => Verifier<number>;
export declare const isANumber: Verifier<unknown>;
