title: How to add value to a ProtoBuf repeated field in C#
body: <p>I am new to Grpc and I wish to make a list of value for a request and in order to do that I need a repeater.  The code is shown below.</p>
  <pre><code>syntax = &quot;proto3&quot;;
  
  option csharp_namespace = &quot;Test.Grpc.Server.Protos&quot;;
  
  package test;
  
  service VcaAdministrator {
      rpc ForceStop (ForceStopRequest) returns (ForceStopResponse);
  }
  
  message ForceStopRequest{
      repeated string Id = 1;
  }
  
  message ForceStopResponse{
      bool stopped = 1;
  }
  </code></pre>
  <p>I wish to pass value to the ForceStopRequest.</p>
  <pre><code>        var cmd = new Command(&quot;ForceStop&quot;);
          cmd.AddOption(new Option&lt;string&gt;(&quot;--id&quot;, getDefaultValue: () =&gt; &quot;null&quot;, description:&quot;Force stop&quot;));
  
          cmd.Handler = CommandHandler.Create(async (List&lt;string&gt; id) =&gt;
          {
              var request = new ForceStopVcaRequest()
              {
                  Id = id
              };
  
              var response = await vcaAdministratorClient.ForceStopVcaAsync(request);
              Console.WriteLine($&quot;{response.Stopped} {response.ErrorCode} {response.ErrorMessage}&quot;);
          });
  
          return cmd;
  </code></pre>
  <p>But the code above generate an error &quot;Property or indexer 'ForceStopRequest.Id' cannot be assigned to -- it is read only.&quot;  How to fix this issue?</p>