@Test
  public void testOperationsWhenNotRunning() throws StoreException, IOException {
    fileStore.stop();
    expectedException.expect(FileStoreException.class);
    expectedException.expectMessage("FileStore is not running");
    fileStore.readStoreFileChunkFromDisk("test.txt", 0, 10, false);
  }
Tests that operations fail when FileStore is not running.
Expects FileStoreException with appropriate message.
ambry-store/src/test/java/com/github/ambry/store/FileStoreTest.java