public Builder SetO(global::Google.ProtocolBuffers.TestProtos.TestRequiredOptimizedForSize value)
 {
     pb::ThrowHelper.ThrowIfNull(value, "value");
     result.hasO = true;
     result.o_   = value;
     return(this);
 }
 public Builder MergeO(global::Google.ProtocolBuffers.TestProtos.TestRequiredOptimizedForSize value)
 {
     pb::ThrowHelper.ThrowIfNull(value, "value");
     if (result.HasO &&
         result.o_ != global::Google.ProtocolBuffers.TestProtos.TestRequiredOptimizedForSize.DefaultInstance)
     {
         result.o_ = global::Google.ProtocolBuffers.TestProtos.TestRequiredOptimizedForSize.CreateBuilder(result.o_).MergeFrom(value).BuildPartial();
     }
     else
     {
         result.o_ = value;
     }
     result.hasO = true;
     return(this);
 }