Add more NativeTokensBuilder helpers

bee-message/src/output/native_token.rs

@@ -55,7 +55,7 @@ fn verify_amount<const VERIFY: bool>(amount: &U256) -> Result<(), Error> {
 }
 
 /// A builder for [`NativeTokens`].
-#[derive(Default)]
+#[derive(Clone, Default, Debug)]
 #[must_use]
 pub struct NativeTokensBuilder(HashMap<TokenId, U256>);
 
@@ -85,6 +85,30 @@ impl NativeTokensBuilder {
  Ok(())
  }
 
+ /// Merges another [`NativeTokensBuilder`] into this one.
+ pub fn merge(&mut self, other: NativeTokensBuilder) -> Result<(), Error> {
+ for (token_id, amount) in other.0.into_iter() {
+ self.add_native_token(NativeToken::new(token_id, amount)?)?;
+ }
+
+ Ok(())
+ }
+
+ /// Returns whether the [`NativeTokensBuilder`] is empty or not.
+ pub fn is_empty(&self) -> bool {
+ self.0.is_empty()
+ }
+
+ /// Gets an amount from the [`NativeTokensBuilder`].
+ pub fn get(&self, token_id: &TokenId) -> Option<&U256> {
+ self.0.get(token_id)
+ }
+
+ /// Inserts a new entry in the [`NativeTokensBuilder`].
+ pub fn insert(&mut self, token_id: TokenId, amount: U256) -> Option<U256> {
+ self.0.insert(token_id, amount)
+ }
+
  /// Finishes the [`NativeTokensBuilder`] into [`NativeTokens`].
  pub fn finish(self) -> Result<NativeTokens, Error> {
  NativeTokens::try_from(