Same as https://github.com/facebook/react/issues/10103, but for the server renderer. You can look at implementation in https://github.com/facebook/react/pull/11168 and do something very similar in `ReactPartialRenderer.js`.
const contextTypes = type.contextTypes;
  if (!contextTypes) {
    return emptyObject;
  }
  const maskedContext = {};
  for (const contextName in contextTypes) {
    maskedContext[contextName] = context[contextName];
  }
  return maskedContext;
}
function checkContextTypes(typeSpecs, values, location: string) {