Function verify_ensemble 

pub fn verify_ensemble<'a>(
    formatted: impl IntoIterator<Item = (&'a Path, &'a MetaProperties)>,
    expected_cluster_id: Option<ClusterId>,
    expected_node_id: Option<i32>,
) -> Result<Option<ClusterId>, String>

Kafka’s MetaPropertiesEnsemble.verify, over the readable files of the directories of one node, sorted by path.

The set agrees on one cluster id and one node id, and no two directories share a directory id, and no directory id is reserved. expected_cluster_id and expected_node_id are the ids that the set has to agree with, when they are known. Returns the cluster id of the set: expected_cluster_id when given, else the id of the first file, or None for an empty set.

Errors

Returns Kafka’s message, word for word, for the first disagreement.