private static void CheckForDiagnostics(SyntaxNodeAnalysisContext context, FieldDeclarationSyntax fieldNode, IFieldSymbol fieldSymbol)
    {
      var isStatic = fieldSymbol.IsStatic;
      var isPublic = fieldSymbol.DeclaredAccessibility.HasFlag(Accessibility.Public);
      var isReadOnly = fieldSymbol.IsReadOnly;

      if (!isStatic || !isPublic || !isReadOnly)
      {
        context.ReportDiagnostic(Diagnostic.Create(
          EvaluateManagedBackingFieldsAnalayzer.mustBePublicStaticAndReadonlyRule,
          fieldNode.GetLocation()));
      }
    }