message: [Proof] Add comment for FrozenSubtreeSiblingIterator::new
diff: @@ -256,9 +256,22 @@ pub struct FrozenSubtreeSiblingIterator {
  }
  impl FrozenSubtreeSiblingIterator {
  + /// Constructs a new `FrozenSubtreeSiblingIterator` for an accumulator with given number of
  + /// leaves.
  + ///
  + /// # Panics
  + ///
  + /// Panics if `num_leaves == 0` or `num_leaves > 2^63`.
  pub fn new(num_leaves: u64) -> Self {
  - assert_ne!(num_leaves, 0);
  - assert!(num_leaves <= 1 << 63);
  + assert_ne!(
  + num_leaves, 0,
  + "Subtree sibling is undefined for empty accumulator.",
  + );
  + assert!(
  + num_leaves <= 1 << 63,
  + "An accumulator can have at most 2^63 leaves. Provided num_leaves: {}.",
  + num_leaves,
  + );
  Self {
  current_num_leaves: num_leaves,
  current_level: 0,
  