private GetBlobOperation createOperation(RouterConfig routerConfig, Callback<GetBlobResult> callback) {
    router.currentOperationsCount.incrementAndGet();
    GetBlobOperation op =
        new GetBlobOperation(routerConfig, routerMetrics, mockClusterMap, responseHandler, blobId, options, callback,
            routerCallback, blobIdFactory, kms, cryptoService, cryptoJobHandler, time, false, quotaChargeCallback,
            this.blobMetadataCache, router, compressionService);
    requestRegistrationCallback.setRequestsToSend(new ArrayList<>());
    return op;
  }
Create a getBlob operation with the specified callback
@param routerConfig the routerConfig used to instantiate GetBlobOperation.
@param callback the callback to run after completion of the operation, or {@code null} if no callback.
@return the operation
ambry-router/src/test/java/com/github/ambry/router/GetBlobOperationTest.java