finalizeInitialChildren.js

  finalizeInitialChildren(
    domElement,
    type,
    props,
    rootContainerInstance,
    hostContext
  ) {
    const { children, ...otherProps } = props;
    Object.keys(otherProps).forEach(attr => {
      if (attr === 'className') {
        domElement.class = otherProps[attr];
      } else if (attr === 'onClick') {
        const listener = otherProps[attr];
        if (domElement.__ourVeryHackCacheOfEventListeners) {
          domElement.__ourVeryHackCacheOfEventListeners.push(listener)
        } else {
          domElement.__ourVeryHackCacheOfEventListeners = [ listener ]
        }
        domElement.addEventListener('click', listener);
      } else {
        throw new Error('TODO: We haven\'t handled other properties/attributes')
      }
    })
  },