private void WriteTimestamp(TextWriter writer, IMessage value)
{
// TODO: In the common case where this *is* using the built-in Timestamp type, we could
// avoid all the reflection at this point, by casting to Timestamp. In the interests of
// avoiding subtle bugs, don't do that until we've implemented DynamicMessage so that we can prove
// it still works in that case.
int nanos = (int) value.Descriptor.Fields[Timestamp.NanosFieldNumber].Accessor.GetValue(value);
long seconds = (long) value.Descriptor.Fields[Timestamp.SecondsFieldNumber].Accessor.GetValue(value);
writer.Write(Timestamp.ToJson(seconds, nanos, DiagnosticOnly));
}