text: export const getClass = obj => ({}.toString.call(obj).slice(8, -1));
  
  export const isFunction = obj => getClass(obj) === 'Function';
  export const isArray = obj => getClass(obj) === 'Array';
  export const isNumber = obj => getClass(obj) === 'Number';
  export const isString = obj => getClass(obj) === 'String';
  export const isObject = obj => getClass(obj) === 'Object';
  export const isBoolean = obj => getClass(obj) === 'Boolean';
  export const isNull = obj => getClass(obj) === 'Null';
  export const isUndefined = obj => getClass(obj) === 'Undefined';
  