message: more clear leaf_count
diff: @@ -29,7 +29,7 @@ impl Entry {
  /// Number of leaves under this node.
  pub fn leaf_count(&self) -> u64 {
  - self.data.end_height - self.data.start_height + 1
  + self.data.end_height - (self.data.start_height - 1)
  }
  /// Is this node a leaf.
  