Returns nil even err != nil if the error type is ignorable.

Marker error: The test requires human interaction.

Marker error: The test is not yet implemented.

Marker error: Mock.

Marker error: The test requires some resource, but the resource is not available.

Marker error: The test requires no test.

Marker error: The test will be done separately as a scenario test.

Marker error: Skip end to end test.

Unsupported UI.