How to get inside an arrow method call of a mocked object using mockito

I have this below method that I need to test using Mockito. In this method, there is a mocked Class object "refDataCache" which calls a method and inside it, there is an arrow function. How to write test, so that I can enter inside the refDataCache.forAllMetaBlock method and check for metaBlockEntity.getMetaBlockId() and metaBlockEntity.getCode().

@GetMapping("/metaBlocks")
    public Map<String, String> getMetaBlock() {
        Map<String, String> response = new HashMap<>();
        refDataCache.forAllMetaBlock(metaBlockEntity ->
                response.put(Long.toString(metaBlockEntity.getMetaBlockId()), metaBlockEntity.getCode())
        );
        return response;
    }

My test code is never able to enter inside the refDataCache.forAllMetaBlock and it directly jumps to return response on debugging.