title: Protobuf "oneof" functionality not working
body: <p>I have a this sample protobuf message:   </p>
  
  <pre><code>message testMessage{    
      oneof oneOfTest{
          string test2 = 2;
          int32 test3 = 3;   
      } 
  }
  </code></pre>
  
  <p>But it is failing to compile, saying:</p>
  
  <pre><code>[ERROR] protoc failed error: Expected "required", "optional", or "repeated".
  test.proto: Missing field number.
  </code></pre>
  
  <p>Based on the line numbers, it is looking for that required/optional/repeated keyworkd before "oneof" and it is complaining of the missing field number after "oneOfTest". Is this not the correct way to use oneof? I am using the java compiler for Protobuf.</p>