code: function isEmpty(obj) {
      var empty = false;
  
      if (isFalsy(obj)) {
          empty = true;
      } else if (isArray(obj)) {
          empty = obj.length === 0;
      } else if (isObject(obj)) {
          empty = Object.keys(obj).length === 0;
      }
  
      return empty;
  }
docs: @member Luc
  Return true if the object is empty.
  {}, [], '',false, null, undefined, NaN
  are all treated as empty.
  
  Luc.isEmpty(true)
  >false
  Luc.isEmpty([])
  >true
  
  @param  {Object}  obj
  @return {Boolean}