Type Alias LogHeights 

pub type LogHeights<A, L> = BTreeMap<A, BTreeMap<L, u32>>;

Map of SeqNum log heights grouped by author A. Each log is identified with L.

Author "panda":
- "trees" log: 6
- "animals" log: 12

Author "icebear":
- "trees" log: 4

Aliased Type

pub struct LogHeights<A, L> { /* private fields */ }