AxBalancerRoutingEvent

type AxBalancerRoutingEvent = Readonly<{
  logicalModel: string;
  namespace: string;
  slice: string;
}> & 
  | Readonly<{
  candidates: readonly AxBalancerCandidateScore[];
  type: "ranked";
}>
  | Readonly<{
  attempt: number;
  routeKey: string;
  serviceName: string;
  type: "selected";
}>
  | Readonly<{
  fromRouteKey: string;
  reason: AxBalancerFailureReason;
  status: number | undefined;
  toRouteKey: string | undefined;
  type: "fallback";
}>
  | Readonly<{
  latencyMs: number | undefined;
  outcome: AxBalancerStatsObservation["outcome"];
  reason:   | AxBalancerFailureReason
     | undefined;
  routeKey: string;
  serviceName: string;
  status: number | undefined;
  streaming: boolean;
  type: "observation";
}>
  | Readonly<{
  errorType: string;
  operation: "get" | "observe";
  routeKey: string;
  type: "store-error";
}>;