Questions on packet-kafka.c

Hello,

I have some observations on packet-kafka.c, that do not look correct to me. Can somebody comment on them ? (I am very new to this so please forgive me if this question is trivial).

1) No attempt to call proto_item_add_subtree(ti, ett_kafka_metadata_topics); 
     yet "ett_kafka_metadata_topics" is contained in an array that is passed to 
     proto_register_subtree_array(..);


There are multiple invocations of the following where the second argument
is not unique. Is this a problem ?
subtree = proto_item_add_subtree(ti, ett_kafka_request_partition);
subtree = proto_item_add_subtree(ti, ett_kafka_request_topic);
subtree = proto_item_add_subtree(ti, ett_kafka_response_partition);
subtree = proto_item_add_subtree(ti, ett_kafka_response_topic);