code: function isFlattenable(value) {
    return isArray_1(value) || isArguments_1(value) ||
      !!(spreadableSymbol && value && value[spreadableSymbol]);
  }
docs: Checks if `value` is a flattenable `arguments` object or array.
  
  @private
  @param {*} value The value to check.
  @returns {boolean} Returns `true` if `value` is flattenable, else `false`.