public MessageExt lookMessageByOffset(final long commitLogOffset) {
        return this.store.lookMessageByOffset(commitLogOffset);
    }
@Test
    public void testLookMessageByOffset() {
        when(messageStore.lookMessageByOffset(anyLong())).thenReturn(new MessageExt());
        MessageExt messageExt = transactionBridge.lookMessageByOffset(123);
        assertThat(messageExt).isNotNull();
    }