/// Common trait for armdb collections managed by [`Db`](super::tree_db::Db).
////// Implemented for `TypedTree`, `TypedMap`, `ZeroTree`, `ZeroMap`
/// where the value type implements [`CollectionMeta`](crate::CollectionMeta).
pubtraitCollection: Send + Sync {/// Collection name (from `CollectionMeta::NAME`).
fnname(&self)->&str;/// Number of entries in the collection.
fnlen(&self)->usize;fnis_empty(&self)->bool{self.len()==0}/// Run a compaction pass across all shards.
fncompact(&self)->crate::DbResult<usize>;}