'Returns the current list of AWS services and a list of service
categories that applies to each one. You then use service
names and categories in your CreateCase requests. Each AWS
service has its own set of categories.
The service codes and category codes correspond to the values
that are displayed in the **Service** and **Category** drop-
down lists on the AWS Support Center `Open a new case`_ page.
The values in those fields, however, do not necessarily match
the service codes and categories returned by the
`DescribeServices` request. Always use the service codes and
categories obtained programmatically. This practice ensures
that you always have the most recent set of service and
category codes.
:type service_code_list: list
:param service_code_list: A JSON-formatted list of service codes
available for AWS services.
:type language: string
:param language: The ISO 639-1 code for the language in which AWS
provides support. AWS Support currently supports English ("en") and
Japanese ("ja"). Language parameters must be passed explicitly for
operations that take them.'

def describe_services(self, service_code_list=None, language=None):

    params = {}
    if (service_code_list is not None):
        params['serviceCodeList'] = service_code_list
    if (language is not None):
        params['language'] = language
    return self.make_request(action='DescribeServices', body=json.dumps(params))
