message: impl Clone for ExtendedFullViewingKey
diff: @@ -131,6 +131,18 @@ impl<E: JubjubEngine> ExpandedSpendingKey<E> {
  }
  }
  +impl<E: JubjubEngine> Clone for FullViewingKey<E> {
  + fn clone(&self) -> Self {
  + FullViewingKey {
  + vk: ViewingKey {
  + ak: self.vk.ak.clone(),
  + nk: self.vk.nk.clone(),
  + },
  + ovk: self.ovk.clone(),
  + }
  + }
  +}
  +
  impl<E: JubjubEngine> FullViewingKey<E> {
  fn from_expanded_spending_key(expsk: &ExpandedSpendingKey<E>, params: &E::Params) -> Self {
  FullViewingKey {
  @@ -351,6 +363,7 @@ pub struct ExtendedSpendingKey {
  }
  // A Sapling extended full viewing key
  +#[derive(Clone)]
  pub struct ExtendedFullViewingKey {
  depth: u8,
  parent_fvk_tag: FVKTag,
  