/**
 * Represents precondition class like in Guava, in order to assert
 * and report fail-fast informative.
 */
export declare class Preconditions {
    /**
     * Asserts and throws if the object `what` is undefined or null.
     *
     * This function compare if the what object is strictly
     * equal to undefined or null, since some special case still
     * become defined such as `false` or `0` as an number.
     *
     * ```
     * Preconditions.notNull(null); // throw "Expect not to be undefined"
     * Preconditions.notNull(undefined); // throw "Expect not to be undefined"
     * Preconditions.notNull(false); // not throw anything
     * Preconditions.notNull(0); // not throw anything
     * ```
     *
     * @param what an object to make a compare
     * @param message a message to report
     */
    static notNull(what: any, message?: string): void;
}