docs: def retrieve(self, id) :
          """
          Retrieve a single source
  
          Returns a single source available to the user by the provided id
          If a source with the supplied unique identifier does not exist it returns an error
  
          :calls: ``get /deal_sources/{id}``
          :param int id: Unique identifier of a DealSource.
          :return: Dictionary that support attriubte-style access and represent DealSource resource.
          :rtype: dict
          """
  
          _, _, deal_source = self.http_client.get("/deal_sources/{id}".format(id=id))
          return deal_source