/**
 * This method is like `sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
 *
 * Differences from lodash:
 * - does not skip `undefined` values
 *
 * Contribution to minified bundle size, when it is the only function imported:
 * - Lodash: 8,292 bytes
 * - Micro-dash: 22 bytes
 */
export declare function sumBy<T>(array: T[], iteratee: (element: T) => number): number;