This DEV-only field was added in 836331ba5f69f2cc53b273ec073fae116db14302 by @sebmarkbage but it's not being used anymore to my knowledge.
outerMemoType = null;
        }
        
        const outerPropTypes = outerMemoType && (outerMemoType: any).propTypes;
        if (outerPropTypes) {
          checkPropTypes(
            outerPropTypes,
            nextProps, 
            'prop',
            getComponentNameFromType(outerMemoType),
          );
        }
      }
    }
  }
  if (current !== null) {
    const prevProps = current.memoizedProps;
    if (
      shallowEqual(prevProps, nextProps) &&
      current.ref === workInProgress.ref &&
      
      (__DEV__ ? workInProgress.type === current.type : true)
    ) {
      didReceiveUpdate = false;
      if (!includesSomeLane(renderLanes, updateLanes)) {