code: def serializer_class(self):
          
          serializer_class = self._serializer_class
          if not isinstance(serializer_class, six.string_types):
              return serializer_class
  
          parts = serializer_class.split('.')
          module_path = '.'.join(parts[:-1])
          if not module_path:
              if getattr(self, 'parent', None) is None:
                  raise Exception(
                      "Can not load serializer '%s'" % serializer_class +
                      ' before binding or without specifying full path')
  
              # try the module of the parent class
              module_path = self.parent.__module__
  
          module = importlib.import_module(module_path)
          serializer_class = getattr(module, parts[-1])
  
          self._serializer_class = serializer_class
          return serializer_class
docs: Get the class of the child serializer.
  
          Resolves string imports.