Any warnings driven off of `warnAboutDeprecatedLifecycles` should use `shared/lowPriorityWarning` rather than `fbjs/lib/warning` to avoid thrashing automated tests.
$$typeof !== REACT_PORTAL_TYPE,
            'Portals are not currently supported by the server renderer. ' +
              'Render them conditionally so that they only appear on the client render.',
          );
          
          invariant(
            false,
            'Unknown element-like object type: %s. This is likely a bug in React. ' +
              'Please file an issue.',
            ($$typeof: any).toString(),
          );
        }
        const nextChildren = toArray(nextChild);
        const frame: Frame = {
          type: null,
          domNamespace: parentNamespace,
          children: nextChildren,
          childIndex: 0,
          context: context,
          footer: '',
        };
        if (__DEV__) {
          ((frame: any): FrameDev).debugElementStack = [];
        }
        this.stack.push(frame);
        return '';
      }
      
      const nextElement = ((nextChild: any): ReactElement);
      const elementType = nextElement.type;