docs: def checkout(cls, order, **kwargs):
          """Checkout cart.
  
          Checkout cart, Making an order.
          This method makes a synchronous HTTP request by default. To make an
          asynchronous HTTP request, please pass async=True
          >>> thread = api.checkout(order, async=True)
          >>> result = thread.get()
  
          :param async bool
          :param Order order: Required order details. (required)
          :return: Order
                   If the method is called asynchronously,
                   returns the request thread.
          """
          kwargs['_return_http_data_only'] = True
          if kwargs.get('async'):
              return cls._checkout_with_http_info(order, **kwargs)
          else:
              (data) = cls._checkout_with_http_info(order, **kwargs)
              return data