This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

'SslProtocols.Tls' is obsolete: 'TLS versions 1.0 and 1.1 have known vulnerabilities and are not recommended. Use a newer TLS version instead, or use SslProtocols.None to defer to OS defaults.' (https://aka.ms/dotnet-warnings/SYSLIB0039)

This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

The field 'Program._client' is never used

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

'WebRequest.CreateHttp(string)' is obsolete: 'WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete. Use HttpClient instead.' (https://aka.ms/dotnet-warnings/SYSLIB0014)

Public method 'Test2' on test class 'ExcelReaderTests' should be marked as a Fact. Reduce the visibility of the method, or add a Fact attribute to the method. (https://xunit.net/xunit.analyzers/rules/xUnit1013)

Test methods should not use blocking task operations, as they can cause deadlocks. Use an async test method and await instead. (https://xunit.net/xunit.analyzers/rules/xUnit1031)