text: const isArray = arr => Array.isArray(arr);
  const isObject = obj => !!obj && typeof obj === 'object';
  const isNumber = i => typeof i !== 'boolean' && !isArray(i) && (typeof i === 'number' || !Number.isNaN(+i));
  const isFunction = func => !!func && func instanceof Function;
  const isEmptyArray = arr => isArray(arr) && arr.length === 0;
  const isEmptyObject = obj => isObject(obj) && Object.keys(obj).length === 0 && obj.constructor === Object;
  
  export {
    isNumber,
    isArray,
    isObject,
    isFunction,
    isEmptyArray,
    isEmptyObject
  };
  