public void RegisterCompilationStartAction(DiagnosticAnalyzer analyzer, Action <CompilationStartAnalysisContext> action)
        {
            CompilationStartAnalyzerAction analyzerAction = new CompilationStartAnalyzerAction(action, analyzer);

            this.GetOrCreateAnalyzerActions(analyzer).AddCompilationStartAction(analyzerAction);
            _compilationStartActions = _compilationStartActions.Add(analyzerAction);
        }
 internal void AddCompilationStartAction(CompilationStartAnalyzerAction action)
 {
     _compilationStartActions = _compilationStartActions.Add(action);
 }