"io.k8s.api.autoscaling.v2.ExternalMetricSource": {
      "description": "ExternalMetricSource indicates how to scale on a metric not associated with any Kubernetes object (for example length of queue in cloud messaging service, or QPS from loadbalancer running outside of cluster).",
      "properties": {
        "metric": {
          "$ref": "#/definitions/io.k8s.api.autoscaling.v2.MetricIdentifier",