Doc(
            """
            'Whitelist' validation step. The parameter field will be the single one
            allowed by the alias or set of aliases defined.
            """
        ),
    ] = None,
    serialization_alias: Annotated[
        Union[str, None],
        Doc(
            """
            'Blacklist' validation step. The vanilla parameter field will be the

              "format": "time_series",
              "instant": false,
              "intervalFactor": 2,
              "legendFormat": "Virtual Memory",
              "refId": "I",
              "step": 2
            },
            {
              "datasource": {
                "type": "prometheus",
                "uid": "${datasource}"
              },

          "instant": true,
          "interval": "",
          "intervalFactor": 1,
          "legendFormat": "{{instance}}",
          "metric": "process_start_time_seconds",
          "refId": "A",
          "step": 60
        }
      ],
      "title": "Uptime",
      "type": "stat"
    },
    {
      "datasource": {
        "type": "prometheus",
        "uid": "${DS_PROMETHEUS}"
      },

//	policyFunc    - function to return bucketPolicy statement which would permit the anonymous request to be served.
//
// The test works in 2 steps, here is the description of the steps.
//
//	STEP 1: Call the handler with the unsigned HTTP request (anonReq), assert for the `ErrAccessDenied` error response.

	var nVersions int // captures all non-free versions

	// Our result
	merged = make([]xlMetaV2ShallowVersion, 0, len(versions[0]))
	tops := make([]xlMetaV2ShallowVersion, len(versions))
	for {
		// Step 1 create slice with all top versions.
		tops = tops[:0]
		var topSig xlMetaV2VersionHeader
		consistent := true // Are all signatures consistent (shortcut)
		for _, vers := range versions {
			if len(vers) == 0 {