in TeamCity.ServiceMessages/Write/Special/Impl/Writer/TeamCityCompilationBlockWriter.cs [33:40]
public TCloseBlock OpenCompilationBlock(string compilerName)
{
if (compilerName == null) throw new ArgumentNullException(nameof(compilerName));
AssertNoChildOpened();
PostMessage(new ServiceMessage("compilationStarted") {{"compiler", compilerName}});
_isChildOpenned++;
return _closeBlock(new DisposableDelegate(() => CloseBlock(compilerName)));
}