pub trait DataPersistenceProxyInterface: Send + Sync {
type PersistResponseFut: Future<Output = Result<PersistResult, Error>> + Send;
type PersistTagsResponseFut: Future<Output = Result<Vec<PersistResult>, Error>> + Send;
// Required methods
fn persist(&self, tag: &str) -> Self::PersistResponseFut;
fn persist_tags(&self, tags: &[String]) -> Self::PersistTagsResponseFut;
}