private void setServerResponse(boolean shouldRespond) {
    for (DataNodeId dataNodeId : clusterMap.getDataNodeIds()) {
      MockServer server = serverLayout.getMockServer(dataNodeId.getHostname(), dataNodeId.getPort());
      server.setShouldRespond(shouldRespond);
    }
  }
Sets all the servers if they should respond requests or not.

@param shouldRespond {@code true} if the servers should respond, otherwise {@code false}.
ambry-router/src/test/java/com/github/ambry/router/DeleteManagerTest.java