message: Throw on null token
diff: @@ -7,6 +7,7 @@ import { PromiseCache } from "@fluidframework/common-utils";
  import { IFluidCodeDetails, IRequest, isFluidPackage } from "@fluidframework/core-interfaces";
  import { IResolvedUrl, IUrlResolver } from "@fluidframework/driver-definitions";
  import { ITelemetryBaseLogger, ITelemetryLogger } from "@fluidframework/common-definitions";
  +import { fetchTokenErrorCode, throwOdspNetworkError } from "@fluidframework/odsp-doclib-utils";
  import { ChildLogger, PerformanceEvent } from "@fluidframework/telemetry-utils";
  import { getLocatorFromOdspUrl, storeLocatorInOdspUrl, encodeOdspFluidDataStoreLocator } from "./odspFluidFileLink";
  import { IOdspResolvedUrl, OdspDocumentInfo, OdspFluidDataStoreLocator, SharingLinkHeader } from "./contracts";
  @@ -127,6 +128,9 @@ export class OdspDriverUrlResolverForShareLink implements IUrlResolver {
  logger,
  { eventName: "GetSharingLinkToken" },
  async (event) => tokenFetcher(options).then((tokenResponse) => {
  + if (tokenResponse === null) {
  + throwOdspNetworkError("Share link Token is null", fetchTokenErrorCode);
  + }
  event.end({ fromCache: isTokenFromCache(tokenResponse) });
  return tokenResponse;
  }));
  