[azuredevops/test] Neither GetBuildCodeCoverage nor GetTestRunCodeCoverage returns results

code:

imports (
	"github.com/microsoft/azure-devops-go-api/azuredevops/v6"
	"github.com/microsoft/azure-devops-go-api/azuredevops/v6/test"
)

	ctx := context.Background()
	organizationUrl := "myorganizationUrl"
	personalAccessToken := "myPersonalAccessToken "
	projectName := "myProjec"
	buildId := 111111
	testRunId := 222222
        flag := 7 // 1,2,4 ???
	conn := azuredevops.NewPatConnection(organizationUrl, personalAccessToken)
	testClient, err := test.NewClient(ctx, conn)
	if err != nil {
		log.Fatal(err)
	}

	coverage, err := testClient.GetBuildCodeCoverage(ctx, test.GetBuildCodeCoverageArgs{
		Project: &projectName,
		BuildId: &buildId,
		Flags:   &flag,
	})
	if err != nil {
		log.Fatal(err)
	}
	_ = coverage


	runCodeCoverage, err := testClient.GetTestRunCodeCoverage(ctx, test.GetTestRunCodeCoverageArgs{
		Project: &projectName,
		RunId:   &testRunId,
		Flags:   &flag,
	})
	if err != nil {
		log.Fatal(err)
	}
	_ = runCodeCoverage

Neither GetBuildCodeCoverage nor GetTestRunCodeCoverage returns results.
At the same time, there is another question about the options for the value of flags.

Start with the GetBuildCodeCoverage and GetTestRunCodeCoverage entry points in the azuredevops/test client and reproduce the calls using the supplied arguments. Inspect how the flags values are defined and interpreted; done means both methods return the expected code-coverage results and the valid flag options are clear.