code: def get_available_options(self, service_name):
          
          options = {}
  
          for data_dir in self.data_dirs:
              # Traverse all the directories trying to find the best match.
              service_glob = "{0}-*.json".format(service_name)
              path = os.path.join(data_dir, service_glob)
              found = glob.glob(path)
  
              for match in found:
                  # Rip apart the path to determine the API version.
                  base = os.path.basename(match)
                  bits = os.path.splitext(base)[0].split('-', 1)
  
                  if len(bits) < 2:
                      continue
  
                  api_version = bits[1]
                  options.setdefault(api_version, [])
                  options[api_version].append(match)
  
          return options
docs: Fetches a collection of all JSON files for a given service.
  
          This checks user-created files (if present) as well as including the
          default service files.
  
          Example::
  
              >>> loader.get_available_options('s3')
              {
                  '2013-11-27': [
                      '~/.boto-overrides/s3-2013-11-27.json',
                      '/path/to/kotocore/data/aws/resources/s3-2013-11-27.json',
                  ],
                  '2010-10-06': [
                      '/path/to/kotocore/data/aws/resources/s3-2010-10-06.json',
                  ],
                  '2007-09-15': [
                      '~/.boto-overrides/s3-2007-09-15.json',
                  ],
              }
  
          :param service_name: The name of the desired service
          :type service_name: string
  
          :returns: A dictionary of api_version keys, with a list of filepaths
              for that version (in preferential order).
          :rtype: dict