code: def _get_schema(self, argmap, req):
          
          if isinstance(argmap, ma.Schema):
              schema = argmap
          elif isinstance(argmap, type) and issubclass(argmap, ma.Schema):
              schema = argmap()
          elif callable(argmap):
              schema = argmap(req)
          else:
              schema = dict2schema(argmap, self.schema_class)()
          if MARSHMALLOW_VERSION_INFO[0] < 3 and not schema.strict:
              warnings.warn(
                  "It is highly recommended that you set strict=True on your schema "
                  "so that the parser's error handler will be invoked when expected.",
                  UserWarning,
              )
          return schema
docs: Return a `marshmallow.Schema` for the given argmap and request.
  
          :param argmap: Either a `marshmallow.Schema`, `dict`
              of argname -> `marshmallow.fields.Field` pairs, or a callable that returns
              a `marshmallow.Schema` instance.
          :param req: The request object being parsed.
          :rtype: marshmallow.Schema