Possible null reference return.

Non-nullable property 'InterfaceType' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'ProjectedClassType' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Clsids' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Avoid multiple blank lines (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide2000)

Remove unused parameter 'extension' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide0060)

Member 'SlowMethod3' does not access instance data and can be marked as static (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1822)

Member 'SlowMethod2' does not access instance data and can be marked as static (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1822)

Type 'TestClass' can be sealed because it has no subtypes in its containing assembly and is not externally visible (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1852)

Dereference of a possibly null reference.

Member 'SlowMethod2' does not access instance data and can be marked as static (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1822)

Member 'SlowMethod3' does not access instance data and can be marked as static (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1822)

Type 'TestClass' can be sealed because it has no subtypes in its containing assembly and is not externally visible (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1852)

Possible null reference return.

Dereference of a possibly null reference.

Avoid multiple blank lines (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide2000)

Remove unused parameter 'extension' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide0060)

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.

Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.

Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.

Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.

Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.

Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.

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.

Non-nullable field 'ResetBackupDirectory' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'OpenBackupDirectory' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.