git.delta.rocks / unique-network / refs/commits / c9c7549767f0

--- a/crates/evm-coder/procedural/src/solidity_interface.rs
+++ b/crates/evm-coder/procedural/src/solidity_interface.rs
@@ -560,6 +560,7 @@
 	selector: u32,
 	args: Vec<MethodArg>,
 	has_normal_args: bool,
+	has_value_args: bool,
 	mutability: Mutability,
 	result: Type,
 	weight: Option<Expr>,
@@ -647,14 +648,20 @@
 			.unwrap_or_else(|| cases::camelcase::to_camel_case(&ident.to_string()));
 		let mut selector_str = camel_name.clone();
 		selector_str.push('(');
-		let mut has_normal_args = false;
-		for (i, arg) in args.iter().filter(|arg| !arg.is_special()).enumerate() {
-			if i != 0 {
-				selector_str.push(',');
+		let mut normal_args_count = 0u32;
+		let mut has_value_args = false;
+		for arg in args.iter() {
+			if arg.is_value() {
+				has_value_args = true;
+			} else if !arg.is_special() {
+				if normal_args_count != 0 {
+					selector_str.push(',');
+				}
+				write!(selector_str, "{}", arg.selector_ty()).unwrap();
+				normal_args_count = normal_args_count.saturating_add(1);
 			}
-			write!(selector_str, "{}", arg.selector_ty()).unwrap();
-			has_normal_args = true;
 		}
+		let has_normal_args = normal_args_count > 0;
 		selector_str.push(')');
 		let selector = fn_selector_str(&selector_str);
 
@@ -667,6 +674,7 @@
 			selector,
 			args,
 			has_normal_args,
+			has_value_args,
 			mutability,
 			result: result.clone(),
 			weight,
@@ -823,7 +831,7 @@
 		let docs = &self.docs;
 		let selector_str = &self.selector_str;
 		let selector = self.selector;
-
+		let is_payable = self.has_value_args;
 		quote! {
 			SolidityFunction {
 				docs: &[#(#docs),*],
@@ -831,6 +839,7 @@
 				selector: #selector,
 				name: #camel_name,
 				mutability: #mutability,
+				is_payable: #is_payable,
 				args: (
 					#(
 						#args,

--- a/crates/evm-coder/src/solidity.rs
+++ b/crates/evm-coder/src/solidity.rs
@@ -422,6 +422,7 @@
 	pub args: A,
 	pub result: R,
 	pub mutability: SolidityMutability,
+	pub is_payable: bool,
 }
 impl<A: SolidityArguments, R: SolidityArguments> SolidityFunctions for SolidityFunction<A, R> {
 	fn solidity_name(
@@ -452,6 +453,9 @@
 			SolidityMutability::View => write!(writer, " view")?,
 			SolidityMutability::Mutable => {}
 		}
+		if self.is_payable {
+			write!(writer, " payable")?;
+		}
 		if !self.result.is_empty() {
 			write!(writer, " returns (")?;
 			self.result.solidity_name(writer, tc)?;

--- a/pallets/common/src/dispatch.rs
+++ b/pallets/common/src/dispatch.rs
@@ -78,6 +78,7 @@
 	/// * `data` - Description of the created collection.
 	fn create(
 		sender: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 	) -> Result<CollectionId, DispatchError>;
 

--- a/pallets/common/src/lib.rs
+++ b/pallets/common/src/lib.rs
@@ -866,6 +866,7 @@
 	/// * `flags` - Extra flags to store.
 	pub fn init_collection(
 		owner: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 		flags: CollectionFlags,
 	) -> Result<CollectionId, DispatchError> {
@@ -939,7 +940,7 @@
 				),
 			);
 			<T as Config>::Currency::settle(
-				owner.as_sub(),
+				payer.as_sub(),
 				imbalance,
 				WithdrawReasons::TRANSFER,
 				ExistenceRequirement::KeepAlive,

--- a/pallets/foreign-assets/src/lib.rs
+++ b/pallets/foreign-assets/src/lib.rs
@@ -309,9 +309,10 @@
 				mode: CollectionMode::Fungible(md.decimals),
 				..Default::default()
 			};
-
+			let owner = T::CrossAccountId::from_sub(owner);
 			let bounded_collection_id = <PalletFungible<T>>::init_foreign_collection(
-				CrossAccountId::from_sub(owner),
+				owner.clone(),
+				owner,
 				data,
 			)?;
 			let foreign_asset_id =

--- a/pallets/fungible/src/lib.rs
+++ b/pallets/fungible/src/lib.rs
@@ -210,18 +210,21 @@
 	/// Initializes the collection. Returns [CollectionId] on success, [DispatchError] otherwise.
 	pub fn init_collection(
 		owner: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 	) -> Result<CollectionId, DispatchError> {
-		<PalletCommon<T>>::init_collection(owner, data, CollectionFlags::default())
+		<PalletCommon<T>>::init_collection(owner, payer, data, CollectionFlags::default())
 	}
 
 	/// Initializes the collection with ForeignCollection flag. Returns [CollectionId] on success, [DispatchError] otherwise.
 	pub fn init_foreign_collection(
 		owner: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 	) -> Result<CollectionId, DispatchError> {
 		let id = <PalletCommon<T>>::init_collection(
 			owner,
+			payer,
 			data,
 			CollectionFlags {
 				foreign: true,

--- a/pallets/nonfungible/src/lib.rs
+++ b/pallets/nonfungible/src/lib.rs
@@ -405,11 +405,13 @@
 	/// - `data`: Contains settings for collection limits and permissions.
 	pub fn init_collection(
 		owner: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 		is_external: bool,
 	) -> Result<CollectionId, DispatchError> {
 		<PalletCommon<T>>::init_collection(
 			owner,
+			payer,
 			data,
 			CollectionFlags {
 				external: is_external,

--- a/pallets/proxy-rmrk-core/src/lib.rs
+++ b/pallets/proxy-rmrk-core/src/lib.rs
@@ -1448,7 +1448,7 @@
 		data: CreateCollectionData<T::AccountId>,
 		properties: impl Iterator<Item = Property>,
 	) -> Result<CollectionId, DispatchError> {
-		let collection_id = <PalletNft<T>>::init_collection(sender, data, true);
+		let collection_id = <PalletNft<T>>::init_collection(sender.clone(), sender, data, true);
 
 		if let Err(DispatchError::Arithmetic(_)) = &collection_id {
 			return Err(<Error<T>>::NoAvailableCollectionId.into());

--- a/pallets/refungible/src/lib.rs
+++ b/pallets/refungible/src/lib.rs
@@ -373,9 +373,10 @@
 	/// - `data`: Contains settings for collection limits and permissions.
 	pub fn init_collection(
 		owner: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 	) -> Result<CollectionId, DispatchError> {
-		<PalletCommon<T>>::init_collection(owner, data, CollectionFlags::default())
+		<PalletCommon<T>>::init_collection(owner, payer, data, CollectionFlags::default())
 	}
 
 	/// Destroy RFT collection

--- a/pallets/unique/src/eth/mod.rs
+++ b/pallets/unique/src/eth/mod.rs
@@ -28,7 +28,7 @@
 		static_property::{key, value as property_value},
 	},
 };
-use pallet_evm_coder_substrate::{SubstrateRecorder, WithRecorder};
+use pallet_evm_coder_substrate::{dispatch_to_evm, SubstrateRecorder, WithRecorder};
 use pallet_evm::{account::CrossAccountId, OnMethodCall, PrecompileHandle, PrecompileResult};
 use up_data_structs::{
 	CollectionName, CollectionDescription, CollectionTokenPrefix, CreateCollectionData,
@@ -156,6 +156,7 @@
 	T: Config + pallet_nonfungible::Config + pallet_refungible::Config,
 >(
 	caller: caller,
+	value: value,
 	name: string,
 	description: string,
 	token_prefix: string,
@@ -172,8 +173,16 @@
 		base_uri_value,
 		add_properties,
 	)?;
+	let value = value.as_u128();
+	let creation_price: Result<u128> = T::CollectionCreationPrice::get()
+		.try_into()
+		.map_err(|_| "collection creation price should be convertible to u128".into());
+	if value != creation_price? {
+		return Err("Sent amount not equals to collection creation price".into());
+	}
+	let collection_helpers_address =  T::CrossAccountId::from_eth(<T as pallet_common::Config>::ContractAddress::get());
 
-	let collection_id = T::CollectionDispatch::create(caller.clone(), data)
+	let collection_id = T::CollectionDispatch::create(caller.clone(), collection_helpers_address, data)
 		.map_err(pallet_evm_coder_substrate::dispatch_to_evm::<T>)?;
 	let address = pallet_common::eth::collection_id_to_address(collection_id);
 	Ok(address)
@@ -183,7 +192,7 @@
 #[solidity_interface(name = CollectionHelpers, events(CollectionHelpersEvents))]
 impl<T> EvmCollectionHelpers<T>
 where
-	T: Config + pallet_nonfungible::Config + pallet_refungible::Config,
+	T: Config + pallet_common::Config + pallet_nonfungible::Config + pallet_refungible::Config,
 {
 	/// Create an NFT collection
 	/// @param name Name of the collection
@@ -209,8 +218,17 @@
 			Default::default(),
 			false,
 		)?;
-		let collection_id = T::CollectionDispatch::create(caller, data)
-			.map_err(pallet_evm_coder_substrate::dispatch_to_evm::<T>)?;
+		let value = value.as_u128();
+		let creation_price: Result<u128> = T::CollectionCreationPrice::get()
+			.try_into()
+			.map_err(|_| "collection creation price should be convertible to u128".into());
+		let creation_price = creation_price?;
+		if value != creation_price {
+			return Err(format!("Sent amount not equals to collection creation price ({0})", creation_price).into());
+		}
+		let collection_helpers_address =  T::CrossAccountId::from_eth(<T as pallet_common::Config>::ContractAddress::get());
+		let collection_id =
+			T::CollectionDispatch::create(caller, collection_helpers_address, data).map_err(dispatch_to_evm::<T>)?;
 
 		let address = pallet_common::eth::collection_id_to_address(collection_id);
 		Ok(address)
@@ -221,6 +239,7 @@
 	fn create_nonfungible_collection_with_properties(
 		&mut self,
 		caller: caller,
+		value: value,
 		name: string,
 		description: string,
 		token_prefix: string,
@@ -236,7 +255,15 @@
 			base_uri_value,
 			true,
 		)?;
-		let collection_id = T::CollectionDispatch::create(caller, data)
+		let value = value.as_u128();
+		let creation_price: Result<u128> = T::CollectionCreationPrice::get()
+			.try_into()
+			.map_err(|_| "collection creation price should be convertible to u128".into());
+		if value != creation_price? {
+			return Err("Sent amount not equals to collection creation price".into());
+		}
+		let collection_helpers_address =  T::CrossAccountId::from_eth(<T as pallet_common::Config>::ContractAddress::get());
+		let collection_id = T::CollectionDispatch::create(caller, collection_helpers_address, data)
 			.map_err(pallet_evm_coder_substrate::dispatch_to_evm::<T>)?;
 
 		let address = pallet_common::eth::collection_id_to_address(collection_id);
@@ -248,12 +275,14 @@
 	fn create_refungible_collection(
 		&mut self,
 		caller: caller,
+		value: value,
 		name: string,
 		description: string,
 		token_prefix: string,
 	) -> Result<address> {
 		create_refungible_collection_internal::<T>(
 			caller,
+			value,
 			name,
 			description,
 			token_prefix,
@@ -267,6 +296,7 @@
 	fn create_refungible_collection_with_properties(
 		&mut self,
 		caller: caller,
+		value: value,
 		name: string,
 		description: string,
 		token_prefix: string,
@@ -274,6 +304,7 @@
 	) -> Result<address> {
 		create_refungible_collection_internal::<T>(
 			caller,
+			value,
 			name,
 			description,
 			token_prefix,

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--- a/pallets/unique/src/eth/stubs/CollectionHelpers.sol
+++ b/pallets/unique/src/eth/stubs/CollectionHelpers.sol
@@ -36,7 +36,7 @@
 		string memory name,
 		string memory description,
 		string memory tokenPrefix
-	) public returns (address) {
+	) public payable returns (address) {
 		require(false, stub_error);
 		name;
 		description;
@@ -52,7 +52,7 @@
 		string memory description,
 		string memory tokenPrefix,
 		string memory baseUri
-	) public returns (address) {
+	) public payable returns (address) {
 		require(false, stub_error);
 		name;
 		description;
@@ -68,7 +68,7 @@
 		string memory name,
 		string memory description,
 		string memory tokenPrefix
-	) public returns (address) {
+	) public payable returns (address) {
 		require(false, stub_error);
 		name;
 		description;
@@ -84,7 +84,7 @@
 		string memory description,
 		string memory tokenPrefix,
 		string memory baseUri
-	) public returns (address) {
+	) public payable returns (address) {
 		require(false, stub_error);
 		name;
 		description;

--- a/pallets/unique/src/lib.rs
+++ b/pallets/unique/src/lib.rs
@@ -344,8 +344,8 @@
 			let sender = ensure_signed(origin)?;
 
 			// =========
-
-			let _id = T::CollectionDispatch::create(T::CrossAccountId::from_sub(sender), data)?;
+			let sender = T::CrossAccountId::from_sub(sender);
+			let _id = T::CollectionDispatch::create(sender.clone(), sender, data)?;
 
 			Ok(())
 		}

--- a/runtime/common/dispatch.rs
+++ b/runtime/common/dispatch.rs
@@ -55,21 +55,22 @@
 {
 	fn create(
 		sender: T::CrossAccountId,
+		payer: T::CrossAccountId,
 		data: CreateCollectionData<T::AccountId>,
 	) -> Result<CollectionId, DispatchError> {
 		let id = match data.mode {
-			CollectionMode::NFT => <PalletNonfungible<T>>::init_collection(sender, data, false)?,
+			CollectionMode::NFT => <PalletNonfungible<T>>::init_collection(sender, payer, data, false)?,
 			CollectionMode::Fungible(decimal_points) => {
 				// check params
 				ensure!(
 					decimal_points <= MAX_DECIMAL_POINTS,
 					pallet_unique::Error::<T>::CollectionDecimalPointLimitExceeded
 				);
-				<PalletFungible<T>>::init_collection(sender, data)?
+				<PalletFungible<T>>::init_collection(sender, payer, data)?
 			}
 
 			#[cfg(feature = "refungible")]
-			CollectionMode::ReFungible => <PalletRefungible<T>>::init_collection(sender, data)?,
+			CollectionMode::ReFungible => <PalletRefungible<T>>::init_collection(sender, payer, data)?,
 
 			#[cfg(not(feature = "refungible"))]
 			CollectionMode::ReFungible => return unsupported!(T),

--- a/tests/src/eth/api/CollectionHelpers.sol
+++ b/tests/src/eth/api/CollectionHelpers.sol
@@ -31,7 +31,7 @@
 		string memory name,
 		string memory description,
 		string memory tokenPrefix
-	) external returns (address);
+	) external payable returns (address);
 
 	/// @dev EVM selector for this function is: 0xa634a5f9,
 	///  or in textual repr: createERC721MetadataCompatibleCollection(string,string,string,string)
@@ -40,7 +40,7 @@
 		string memory description,
 		string memory tokenPrefix,
 		string memory baseUri
-	) external returns (address);
+	) external payable returns (address);
 
 	/// @dev EVM selector for this function is: 0xab173450,
 	///  or in textual repr: createRFTCollection(string,string,string)
@@ -48,7 +48,7 @@
 		string memory name,
 		string memory description,
 		string memory tokenPrefix
-	) external returns (address);
+	) external payable returns (address);
 
 	/// @dev EVM selector for this function is: 0xa5596388,
 	///  or in textual repr: createERC721MetadataCompatibleRFTCollection(string,string,string,string)
@@ -57,7 +57,7 @@
 		string memory description,
 		string memory tokenPrefix,
 		string memory baseUri
-	) external returns (address);
+	) external payable returns (address);
 
 	/// Check if a collection exists
 	/// @param collectionAddress Address of the collection in question

--- a/tests/src/eth/collectionHelpersAbi.json
+++ b/tests/src/eth/collectionHelpersAbi.json
@@ -27,7 +27,7 @@
     ],
     "name": "createERC721MetadataCompatibleCollection",
     "outputs": [{ "internalType": "address", "name": "", "type": "address" }],
-    "stateMutability": "nonpayable",
+    "stateMutability": "payable",
     "type": "function"
   },
   {
@@ -39,7 +39,7 @@
     ],
     "name": "createERC721MetadataCompatibleRFTCollection",
     "outputs": [{ "internalType": "address", "name": "", "type": "address" }],
-    "stateMutability": "nonpayable",
+    "stateMutability": "payable",
     "type": "function"
   },
   {
@@ -50,7 +50,7 @@
     ],
     "name": "createNonfungibleCollection",
     "outputs": [{ "internalType": "address", "name": "", "type": "address" }],
-    "stateMutability": "nonpayable",
+    "stateMutability": "payable",
     "type": "function"
   },
   {
@@ -61,7 +61,7 @@
     ],
     "name": "createRFTCollection",
     "outputs": [{ "internalType": "address", "name": "", "type": "address" }],
-    "stateMutability": "nonpayable",
+    "stateMutability": "payable",
     "type": "function"
   },
   {

--- a/tests/src/eth/fractionalizer/Fractionalizer.sol
+++ b/tests/src/eth/fractionalizer/Fractionalizer.sol
@@ -18,7 +18,8 @@
 	mapping(address => bool) nftCollectionAllowList;
 	mapping(address => mapping(uint256 => uint256)) public nft2rftMapping;
 	mapping(address => Token) public rft2nftMapping;
-	bytes32 refungibleCollectionType = keccak256(bytes("ReFungible"));
+	//use constant to reduce gas cost
+	bytes32 constant refungibleCollectionType = keccak256(bytes("ReFungible"));
 
 	receive() external payable onlyOwner {}
 
@@ -51,11 +52,12 @@
 	///  Throws if `msg.sender` is not owner or admin of provided RFT collection.
 	///  Can only be called by contract owner.
 	/// @param _collection address of RFT collection.
-	function setRFTCollection(address _collection) public onlyOwner {
+	function setRFTCollection(address _collection) external onlyOwner {
 		require(rftCollection == address(0), "RFT collection is already set");
 		UniqueRefungible refungibleContract = UniqueRefungible(_collection);
 		string memory collectionType = refungibleContract.uniqueCollectionType();
 
+		// compare hashed to reduce gas cost
 		require(
 			keccak256(bytes(collectionType)) == refungibleCollectionType,
 			"Wrong collection type. Collection is not refungible."
@@ -79,7 +81,7 @@
 		string calldata _name,
 		string calldata _description,
 		string calldata _tokenPrefix
-	) public onlyOwner {
+	) external onlyOwner {
 		require(rftCollection == address(0), "RFT collection is already set");
 		address collectionHelpers = 0x6C4E9fE1AE37a41E93CEE429e8E1881aBdcbb54F;
 		rftCollection = CollectionHelpers(collectionHelpers).createRFTCollection(_name, _description, _tokenPrefix);
@@ -90,7 +92,7 @@
 	/// @dev Can only be called by contract owner.
 	/// @param collection NFT token address.
 	/// @param status `true` to allow and `false` to disallow NFT token.
-	function setNftCollectionIsAllowed(address collection, bool status) public onlyOwner {
+	function setNftCollectionIsAllowed(address collection, bool status) external onlyOwner {
 		nftCollectionAllowList[collection] = status;
 		emit AllowListSet(collection, status);
 	}
@@ -109,7 +111,7 @@
 		address _collection,
 		uint256 _token,
 		uint128 _pieces
-	) public {
+	) external {
 		require(rftCollection != address(0), "RFT collection is not set");
 		UniqueRefungible rftCollectionContract = UniqueRefungible(rftCollection);
 		require(
@@ -148,7 +150,7 @@
 	///  Throws if `msg.sender` isn't owner of all RFT token pieces.
 	/// @param _collection RFT collection address
 	/// @param _token id of RFT token
-	function rft2nft(address _collection, uint256 _token) public {
+	function rft2nft(address _collection, uint256 _token) external {
 		require(rftCollection != address(0), "RFT collection is not set");
 		require(rftCollection == _collection, "Wrong RFT collection");
 		UniqueRefungible rftCollectionContract = UniqueRefungible(rftCollection);

--- a/tests/src/eth/payable.test.ts
+++ b/tests/src/eth/payable.test.ts
@@ -140,16 +140,13 @@
   });
   
   itEth('Fee for nested calls to native methods is withdrawn from the user', async({helper}) => {
-    const CONTRACT_BALANCE = 3n * helper.balance.getOneTokenNominal();
+    const CONTRACT_BALANCE = 2n * helper.balance.getOneTokenNominal();
 
     const deployer = await helper.eth.createAccountWithBalance(donor);
     const caller = await helper.eth.createAccountWithBalance(donor);
     const contract = await deployProxyContract(helper, deployer);
-    
-    const web3 = helper.getWeb3();
-    await web3.eth.sendTransaction({from: deployer, to: contract.options.address, value: CONTRACT_BALANCE.toString(), gas: helper.eth.DEFAULT_GAS});
 
-    const collectionAddress = (await contract.methods.createNonfungibleCollection().send({from: caller})).events.CollectionCreated.returnValues.collection;
+    const collectionAddress = (await contract.methods.createNonfungibleCollection().send({from: caller, value: Number(CONTRACT_BALANCE)})).events.CollectionCreated.returnValues.collection;
     const initialCallerBalance = await helper.balance.getEthereum(caller);
     const initialContractBalance = await helper.balance.getEthereum(contract.options.address);
     await contract.methods.mintNftToken(collectionAddress).send({from: caller});
@@ -160,22 +157,18 @@
   });
   
   itEth('Fee for nested calls to create*Collection methods is withdrawn from the user and from the contract', async({helper}) => {
-    const CONTRACT_BALANCE = 3n * helper.balance.getOneTokenNominal();
-
+    const CONTRACT_BALANCE = 2n * helper.balance.getOneTokenNominal();
     const deployer = await helper.eth.createAccountWithBalance(donor);
     const caller = await helper.eth.createAccountWithBalance(donor);
     const contract = await deployProxyContract(helper, deployer);
-    
-    const web3 = helper.getWeb3();
-    await web3.eth.sendTransaction({from: deployer, to: contract.options.address, value: CONTRACT_BALANCE.toString(), gas: helper.eth.DEFAULT_GAS});
 
     const initialCallerBalance = await helper.balance.getEthereum(caller);
     const initialContractBalance = await helper.balance.getEthereum(contract.options.address);
-    await contract.methods.createNonfungibleCollection().send({from: caller});
+    await contract.methods.createNonfungibleCollection().send({from: caller, value: Number(CONTRACT_BALANCE)});
     const finalCallerBalance = await helper.balance.getEthereum(caller);
     const finalContractBalance = await helper.balance.getEthereum(contract.options.address);
     expect(finalCallerBalance < initialCallerBalance).to.be.true;
-    expect(finalContractBalance < initialContractBalance).to.be.true;
+    expect(finalContractBalance == initialContractBalance).to.be.true;
   });
 
   async function deployProxyContract(helper: EthUniqueHelper, deployer: string) {
@@ -189,6 +182,8 @@
       import {CollectionHelpers} from "../api/CollectionHelpers.sol";
       import {UniqueNFT} from "../api/UniqueNFT.sol";
 
+      error Value(uint256 value);
+
       contract ProxyContract {
         bool value = false;
         address flipper;
@@ -207,30 +202,30 @@
           Flipper(flipper).flip();
         }
 
-        function createNonfungibleCollection() public {
+        function createNonfungibleCollection() external payable {
           address collectionHelpers = 0x6C4E9fE1AE37a41E93CEE429e8E1881aBdcbb54F;
-		      address nftCollection = CollectionHelpers(collectionHelpers).createNonfungibleCollection("A", "B", "C");
+		      address nftCollection = CollectionHelpers(collectionHelpers).createNonfungibleCollection{value: msg.value}("A", "B", "C");
           emit CollectionCreated(nftCollection);
         }
 
-        function mintNftToken(address collectionAddress) public {
+        function mintNftToken(address collectionAddress) external  {
           UniqueNFT collection = UniqueNFT(collectionAddress);
           uint256 tokenId = collection.nextTokenId();
           collection.mint(msg.sender, tokenId);
           emit TokenMinted(tokenId);
         }
 
-        function getValue() public view returns (bool) {
+        function getValue() external view returns (bool) {
           return Flipper(flipper).getValue();
         }
       }
 
       contract Flipper {
         bool value = false;
-        function flip() public {
+        function flip() external {
           value = !value;
         }
-        function getValue() public view returns (bool) {
+        function getValue() external view returns (bool) {
           return value;
         }
       }