function isNgForOf(path) {
  var node = path.getValue();
  var index = path.getName();
  var parentNode = path.getParentNode();
  return node.type === "NGMicrosyntaxKeyedExpression" && node.key.name === "of" && index === 1 && parentNode.body[0].type === "NGMicrosyntaxLet" && parentNode.body[0].value === null;
}
prefer `let hero of heros` over `let hero; of: heros`