kafkaSimpleStreamConsumer.fetchMessages(12345L, 23456L, 10000); Assert.assertEquals(KafkaStreamConfigProperties.LowLevelConsumer.KAFKA_BUFFER_SIZE_DEFAULT, kafkaSimpleStreamConsumer.getSimpleConsumer().bufferSize()); Assert.assertEquals(KafkaStreamConfigProperties.LowLevelConsumer.KAFKA_SOCKET_TIMEOUT_DEFAULT, kafkaSimpleStreamConsumer.getSimpleConsumer().soTimeout()); new KafkaPartitionLevelConsumer(clientId, streamConfig, 0, mockKafkaSimpleConsumerFactory); kafkaSimpleStreamConsumer.fetchMessages(12345L, 23456L, 10000); Assert.assertEquals(100, kafkaSimpleStreamConsumer.getSimpleConsumer().bufferSize()); Assert.assertEquals(1000, kafkaSimpleStreamConsumer.getSimpleConsumer().soTimeout());