code: def resolve_schema_in_request_body(self, request_body):
          
          content = request_body["content"]
          for content_type in content:
              schema = content[content_type]["schema"]
              content[content_type]["schema"] = self.openapi.resolve_schema_dict(schema)
docs: Function to resolve a schema in a requestBody object - modifies then
          response dict to convert Marshmallow Schema object or class into dict