message: set_at_index sets the default value (0) if index doesn't exist in the other vector
diff: @@ -108,10 +108,8 @@ impl VClock {
  /// Set the element at the current index of the vector
  pub fn set_at_index(&mut self, other: &Self, idx: VectorIdx) {
  - let idx = idx.index();
  - let mut_slice = self.get_mut_with_min_len(idx + 1);
  - let slice = other.as_slice();
  - mut_slice[idx] = slice[idx];
  + let mut_slice = self.get_mut_with_min_len(idx.index() + 1);
  + mut_slice[idx.index()] = other[idx];
  }
  /// Set the vector to the all-zero vector
  