code: def supported_providers(self):
          
          req = self.request(self.uri + '/providers', api_version=2)
          providers = req.get().json()
          supported_providers = providers['supported_providers']
          return supported_providers
docs: Request a list of all available providers
  
          :returns: A list of all available providers (e.g. {'provider':
          'ec2_ap_northeast', 'title': 'EC2 AP NORTHEAST'})