/**
 * Checks whether value is thenable according to Promise A+ spec https://promisesaplus.com/
 * Useful to asses whether value might be used as promise.
 *
 * @example
 * is.thenable(Promise.resolve('test')); // true
 * is.thenable({then: () => {}}); // this is still a thenable (according to spec)
 * is.thenable({}); // false
 */
export default function isThenable(value: any): value is {
    then: (a: Function, b?: Function) => any;
};