private static void CheckCopyrightHeader(SyntaxTreeAnalysisContext context, DocumentationSettings documentationSettings, Compilation compilation, XmlFileHeader fileHeader)
            {
                var copyrightElement = fileHeader.GetElement("copyright");

                if (copyrightElement == null)
                {
                    context.ReportDiagnostic(Diagnostic.Create(SA1634Descriptor, fileHeader.GetLocation(context.Tree)));
                    return;
                }

                if (!compilation.IsAnalyzerSuppressed(SA1637Descriptor))
                {
                    CheckFile(context, compilation, fileHeader, copyrightElement);
                }

                if (!compilation.IsAnalyzerSuppressed(SA1640Descriptor))
                {
                    CheckCompanyName(context, documentationSettings, compilation, fileHeader, copyrightElement);
                }

                if (!compilation.IsAnalyzerSuppressed(SA1635Descriptor))
                {
                    CheckCopyrightText(context, documentationSettings, compilation, fileHeader, copyrightElement);
                }
            }
            private static void CheckSummaryHeader(SyntaxTreeAnalysisContext context, Compilation compilation, XmlFileHeader fileHeader)
            {
                var summaryElement = fileHeader.GetElement("summary");

                if (summaryElement == null)
                {
                    context.ReportDiagnostic(Diagnostic.Create(SA1639Descriptor, fileHeader.GetLocation(context.Tree)));
                    return;
                }

                if (string.IsNullOrWhiteSpace(summaryElement.Value))
                {
                    var location = fileHeader.GetElementLocation(context.Tree, summaryElement);
                    context.ReportDiagnostic(Diagnostic.Create(SA1639Descriptor, location));
                }
            }