src/language-js/utils/index.js/hasFlowShorthandAnnotationComment
function hasFlowShorthandAnnotationComment(node) {
  // https://flow.org/en/docs/types/comments/
  // Syntax example: const r = new (window.Request /*: Class<Request> */)("");

  return (
    node.extra?.parenthesized &&
    isBlockComment(node.trailingComments?.[0]) &&
    FLOW_SHORTHAND_ANNOTATION.test(node.trailingComments[0].value)
  );
}