title: what is the meaning of "Value" class in .proto file
body: <p>can someone please explain me the meaning of "Value" in below .proto file?</p>
  
  <pre class="lang-proto prettyprint-override"><code>message Test {
  string id = 1;
  string name = 2;
  google.protobuf.Value property = 6;}
  </code></pre>