// +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time time = 1;

  // message represents the error encountered during Attach or Detach operation.
  // This string maybe logged, so it should not contain sensitive
  // information.
  // +optional
  optional string message = 2;

}

// Preconditions must be fulfilled before an operation (update, delete, etc.) is carried out.
message Preconditions {
  // Specifies the target UID.
  // +optional
  optional string uid = 1;

  // Specifies the target ResourceVersion
  // +optional
  optional string resourceVersion = 2;
}

// RootPaths lists the paths available at root.
// For example: "/healthz", "/apis".

  // version of both map-based and more expressive set-based selectors. This is done to
  // avoid introspection in the clients. The string will be in the same format as the
  // query-param syntax. If the target type only supports map-based selectors, both this
  // field and map-based selector field are populated.
  // More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
  // +optional

  // must contain a non-empty list.
  // +optional
  optional bool clusterScope = 4;

  // `namespaces` is a list of target namespaces that restricts
  // matches.  A request that specifies a target namespace matches
  // only if either (a) this list contains that target namespace or
  // (b) this list contains "*".  Note that "*" matches any
  // specified namespace but does not match a request that _does

  // must contain a non-empty list.
  // +optional
  optional bool clusterScope = 4;

  // `namespaces` is a list of target namespaces that restricts
  // matches.  A request that specifies a target namespace matches
  // only if either (a) this list contains that target namespace or
  // (b) this list contains "*".  Note that "*" matches any
  // specified namespace but does not match a request that _does

  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time time = 1;

  // message represents the error encountered during Attach or Detach operation.
  // This string may be logged, so it should not contain sensitive
  // information.
  // +optional
  optional string message = 2;
}

// VolumeNodeResources is a set of resource limits for scheduling of volumes.
message VolumeNodeResources {

  // If both message and messageExpression are present on a validation, then messageExpression will be used if validation fails.
  // If messageExpression results in a runtime error, the runtime error is logged, and the validation failure message is produced
  // as if the messageExpression field were unset. If messageExpression evaluates to an empty string, a string with only spaces, or a string

  // must contain a non-empty list.
  // +optional
  optional bool clusterScope = 4;

  // `namespaces` is a list of target namespaces that restricts
  // matches.  A request that specifies a target namespace matches
  // only if either (a) this list contains that target namespace or
  // (b) this list contains "*".  Note that "*" matches any
  // specified namespace but does not match a request that _does

  // must contain a non-empty list.
  // +optional
  optional bool clusterScope = 4;

  // `namespaces` is a list of target namespaces that restricts
  // matches.  A request that specifies a target namespace matches
  // only if either (a) this list contains that target namespace or
  // (b) this list contains "*".  Note that "*" matches any
  // specified namespace but does not match a request that _does

// value.
message PodsMetricSource {
  // metric identifies the target metric by name and selector
  optional MetricIdentifier metric = 1;

  // target specifies the target value for the given metric
  optional MetricTarget target = 2;
}

// PodsMetricStatus indicates the current value of a metric describing each pod in