Вы можете создать ConsumerRecord вместо насмешки, как показано ниже -
Map<TopicPartition, List<ConsumerRecord<Integer, String>>> records = new LinkedHashMap<>();
String topic = "topic";
records.put(new TopicPartition(topic, 0), new ArrayList<ConsumerRecord<Integer, String>>());
ConsumerRecord<Integer, String> record1 = new ConsumerRecord<>(topic, 1, 0, 0L, TimestampType.CREATE_TIME, 0L, 0, 0, 1, "value1");
ConsumerRecord<Integer, String> record2 = new ConsumerRecord<>(topic, 1, 1, 0L, TimestampType.CREATE_TIME, 0L, 0, 0, 2, "value2");
records.put(new TopicPartition(topic, 1), Arrays.asList(record1, record2));
records.put(new TopicPartition(topic, 2), new ArrayList<ConsumerRecord<Integer, String>>());
ConsumerRecords<Integer, String> consumerRecords = new ConsumerRecords<>(records);