Strip down Shell to bare minimum (#421)

* Strip down shell

* Fixes

* Fixes

* Fixes

* Fixes

cumulus/Cargo.lock

@@ -1554,11 +1554,6 @@ dependencies = [
  "hex",
  "hex-literal 0.3.1",
  "log",
- "pallet-balances",
- "pallet-randomness-collective-flip",
- "pallet-timestamp",
- "pallet-transaction-payment",
- "pallet-xcm",
  "parachain-info",
  "parity-scale-codec",
  "polkadot-parachain",

cumulus/pallets/parachain-system/src/lib.rs

@@ -49,6 +49,11 @@ use cumulus_primitives_core::{
 };
 use cumulus_primitives_parachain_inherent::ParachainInherentData;
 use relay_state_snapshot::MessagingStateSnapshot;
+use sp_runtime::transaction_validity::{
+	TransactionSource, TransactionValidity, InvalidTransaction, ValidTransaction,
+	TransactionLongevity,
+};
+use sp_runtime::DispatchError;
 
 mod relay_state_snapshot;
 #[macro_use]
@@ -261,10 +266,7 @@ decl_module! {
 		#[weight = 1_000_000]
 		fn enact_authorized_upgrade(_origin, code: Vec<u8>) -> DispatchResultWithPostInfo {
 			// No ensure origin on purpose. We validate by checking the code vs hash in storage.
-			let required_hash = AuthorizedUpgrade::<T>::get()
+			Self::validate_authorized_upgrade(&code[..])?;
-				.ok_or(Error::<T>::NothingAuthorized)?;
-			let actual_hash = T::Hashing::hash(&code[..]);
-			ensure!(actual_hash == required_hash, Error::<T>::Unauthorized);
 			Self::set_code_impl(code)?;
 			AuthorizedUpgrade::<T>::kill();
 			Ok(Pays::No.into())
@@ -403,6 +405,35 @@ decl_module! {
 	}
 }
 
+impl<T: Config> Module<T> {
+	fn validate_authorized_upgrade(code: &[u8]) -> Result<T::Hash, DispatchError> {
+		let required_hash = AuthorizedUpgrade::<T>::get()
+			.ok_or(Error::<T>::NothingAuthorized)?;
+		let actual_hash = T::Hashing::hash(&code[..]);
+		ensure!(actual_hash == required_hash, Error::<T>::Unauthorized);
+		Ok(actual_hash)
+	}
+}
+
+impl<T: Config> sp_runtime::traits::ValidateUnsigned for Module<T> {
+	type Call = Call<T>;
+
+	fn validate_unsigned(_source: TransactionSource, call: &Self::Call) -> TransactionValidity {
+		if let Call::enact_authorized_upgrade(ref code) = call {
+			if let Ok(hash) = Self::validate_authorized_upgrade(code) {
+				return Ok(ValidTransaction {
+					priority: 100,
+					requires: vec![],
+					provides: vec![hash.as_ref().to_vec()],
+					longevity: TransactionLongevity::max_value(),
+					propagate: true,
+				})
+			}
+		}
+		Err(InvalidTransaction::Call.into())
+	}
+}
+
 impl<T: Config> GetChannelInfo for Module<T> {
 	fn get_channel_status(id: ParaId) -> ChannelStatus {
 		// Note, that we are using `relevant_messaging_state` which may be from the previous

cumulus/rococo-parachains/shell-runtime/Cargo.toml

@@ -27,10 +27,6 @@ sp-inherents = { git = "https://github.com/paritytech/substrate", default-featur
 frame-support = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 frame-executive = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 frame-system = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
-pallet-balances = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
-pallet-randomness-collective-flip = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
-pallet-timestamp = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
-pallet-transaction-payment = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 
 # Cumulus dependencies
 cumulus-pallet-parachain-system = { path = "../../pallets/parachain-system", default-features = false }
@@ -44,7 +40,6 @@ polkadot-parachain = { git = "https://github.com/paritytech/polkadot", default-f
 xcm = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 xcm-builder = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 xcm-executor = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
-pallet-xcm = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
 
 [dev-dependencies]
 hex = "0.4.3"
@@ -73,10 +68,6 @@ std = [
 	"frame-support/std",
 	"frame-executive/std",
 	"frame-system/std",
-	"pallet-balances/std",
-	"pallet-randomness-collective-flip/std",
-	"pallet-timestamp/std",
-	"pallet-transaction-payment/std",
 	"parachain-info/std",
 	"rococo-parachain-primitives/std",
 	"cumulus-pallet-parachain-system/std",

cumulus/rococo-parachains/shell-runtime/src/lib.rs

@@ -26,7 +26,7 @@ use rococo_parachain_primitives::*;
 use sp_api::impl_runtime_apis;
 use sp_core::OpaqueMetadata;
 use sp_runtime::{
-	create_runtime_str, generic, impl_opaque_keys,
+	create_runtime_str, generic,
 	traits::{BlakeTwo256, Block as BlockT, AccountIdLookup},
 	transaction_validity::{TransactionSource, TransactionValidity},
 	ApplyExtrinsicResult,
@@ -38,7 +38,7 @@ use sp_version::RuntimeVersion;
 
 // A few exports that help ease life for downstream crates.
 pub use frame_support::{
-	construct_runtime, parameter_types,
+	construct_runtime, parameter_types, match_type,
 	traits::{Randomness, All, IsInVec},
 	weights::{
 		constants::{BlockExecutionWeight, ExtrinsicBaseWeight, RocksDbWeight, WEIGHT_PER_SECOND},
@@ -47,28 +47,18 @@ pub use frame_support::{
 	StorageValue,
 };
 use frame_system::limits::{BlockLength, BlockWeights};
-pub use pallet_balances::Call as BalancesCall;
-pub use pallet_timestamp::Call as TimestampCall;
 #[cfg(any(feature = "std", test))]
 pub use sp_runtime::BuildStorage;
 pub use sp_runtime::{Perbill, Permill};
 
 // XCM imports
-use polkadot_parachain::primitives::Sibling;
+use xcm::v0::{Junction::*, MultiLocation, MultiLocation::*, NetworkId};
-use xcm::v0::{Junction, MultiLocation, NetworkId};
 use xcm_builder::{
-	AccountId32Aliases, CurrencyAdapter, LocationInverter, ParentIsDefault, RelayChainAsNative,
+	LocationInverter, ParentIsDefault, FixedWeightBounds, AllowUnpaidExecutionFrom,
-	SiblingParachainAsNative, SiblingParachainConvertsVia, SignedAccountId32AsNative,
+	ParentAsSuperuser, SovereignSignedViaLocation,
-	SovereignSignedViaLocation, FixedRateOfConcreteFungible, EnsureXcmOrigin,
-	AllowTopLevelPaidExecutionFrom, TakeWeightCredit, FixedWeightBounds, IsConcrete, NativeAsset,
-	AllowUnpaidExecutionFrom, ParentAsSuperuser,
 };
 use xcm_executor::{Config, XcmExecutor};
 
-impl_opaque_keys! {
-	pub struct SessionKeys {}
-}
-
 /// This runtime version.
 pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("shell"),
@@ -80,20 +70,6 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	transaction_version: 1,
 };
 
-pub const MILLISECS_PER_BLOCK: u64 = 6000;
-
-pub const SLOT_DURATION: u64 = MILLISECS_PER_BLOCK;
-
-pub const EPOCH_DURATION_IN_BLOCKS: u32 = 10 * MINUTES;
-
-// These time units are defined in number of blocks.
-pub const MINUTES: BlockNumber = 60_000 / (MILLISECS_PER_BLOCK as BlockNumber);
-pub const HOURS: BlockNumber = MINUTES * 60;
-pub const DAYS: BlockNumber = HOURS * 24;
-
-// 1 in 4 blocks (on average, not counting collisions) will be primary babe blocks.
-pub const PRIMARY_PROBABILITY: (u64, u64) = (1, 4);
-
 /// The version information used to identify this runtime when compiled natively.
 #[cfg(feature = "std")]
 pub fn native_version() -> NativeVersion {
@@ -103,7 +79,7 @@ pub fn native_version() -> NativeVersion {
 	}
 }
 
-/// We assume that ~10% of the block weight is consumed by `on_initalize` handlers.
+/// We assume that ~10% of the block weight is consumed by `on_initialize` handlers.
 /// This is used to limit the maximal weight of a single extrinsic.
 const AVERAGE_ON_INITIALIZE_RATIO: Perbill = Perbill::from_percent(10);
 /// We allow `Normal` extrinsics to fill up the block up to 75%, the rest can be used
@@ -165,7 +141,7 @@ impl frame_system::Config for Runtime {
 	type Version = Version;
 	/// Converts a module to an index of this module in the runtime.
 	type PalletInfo = PalletInfo;
-	type AccountData = pallet_balances::AccountData<Balance>;
+	type AccountData = ();
 	type OnNewAccount = ();
 	type OnKilledAccount = ();
 	type DbWeight = ();
@@ -178,46 +154,8 @@ impl frame_system::Config for Runtime {
 }
 
 parameter_types! {
-	pub const MinimumPeriod: u64 = SLOT_DURATION / 2;
+	// We do anything the parent chain tells us in this runtime.
-}
+	pub const ReservedDmpWeight: Weight = MAXIMUM_BLOCK_WEIGHT;
-
-impl pallet_timestamp::Config for Runtime {
-	/// A timestamp: milliseconds since the unix epoch.
-	type Moment = u64;
-	type OnTimestampSet = ();
-	type MinimumPeriod = MinimumPeriod;
-	type WeightInfo = ();
-}
-
-parameter_types! {
-	pub const ExistentialDeposit: u128 = 500;
-	pub const TransferFee: u128 = 0;
-	pub const CreationFee: u128 = 0;
-	pub const TransactionByteFee: u128 = 1;
-	pub const MaxLocks: u32 = 50;
-}
-
-impl pallet_balances::Config for Runtime {
-	/// The type for recording an account's balance.
-	type Balance = Balance;
-	/// The ubiquitous event type.
-	type Event = Event;
-	type DustRemoval = ();
-	type ExistentialDeposit = ExistentialDeposit;
-	type AccountStore = System;
-	type WeightInfo = ();
-	type MaxLocks = MaxLocks;
-}
-
-impl pallet_transaction_payment::Config for Runtime {
-	type OnChargeTransaction = pallet_transaction_payment::CurrencyAdapter<Balances, ()>;
-	type TransactionByteFee = TransactionByteFee;
-	type WeightToFee = IdentityFee<Balance>;
-	type FeeMultiplierUpdate = ();
-}
-
-parameter_types! {
-	pub const ReservedXcmpWeight: Weight = MAXIMUM_BLOCK_WEIGHT / 4;
 }
 
 impl cumulus_pallet_parachain_system::Config for Runtime {
@@ -225,124 +163,68 @@ impl cumulus_pallet_parachain_system::Config for Runtime {
 	type OnValidationData = ();
 	type SelfParaId = parachain_info::Module<Runtime>;
 	type DownwardMessageHandlers = CumulusXcm;
-	type OutboundXcmpMessageSource = XcmpQueue;
+	type OutboundXcmpMessageSource = ();
-	type XcmpMessageHandler = XcmpQueue;
+	type XcmpMessageHandler = ();
-	type ReservedXcmpWeight = ReservedXcmpWeight;
+	type ReservedXcmpWeight = ();
 }
 
 impl parachain_info::Config for Runtime {}
 
 parameter_types! {
-	pub const RococoLocation: MultiLocation = MultiLocation::X1(Junction::Parent);
+	pub const RococoLocation: MultiLocation = X1(Parent);
 	pub const RococoNetwork: NetworkId = NetworkId::Polkadot;
-	pub RelayChainOrigin: Origin = cumulus_pallet_xcm::Origin::Relay.into();
+	pub Ancestry: MultiLocation = Parachain(ParachainInfo::parachain_id().into()).into();
-	pub Ancestry: MultiLocation = Junction::Parachain(
-		ParachainInfo::parachain_id().into()
-	).into();
 }
 
-/// Type for specifying how a `MultiLocation` can be converted into an `AccountId`. This is used
-/// when determining ownership of accounts for asset transacting and when attempting to use XCM
-/// `Transact` in order to determine the dispatch Origin.
-pub type LocationToAccountId = (
-	// The parent (Relay-chain) origin converts to the default `AccountId`.
-	ParentIsDefault<AccountId>,
-	// Sibling parachain origins convert to AccountId via the `ParaId::into`.
-	SiblingParachainConvertsVia<Sibling, AccountId>,
-	// Straight up local `AccountId32` origins just alias directly to `AccountId`.
-	AccountId32Aliases<RococoNetwork, AccountId>,
-);
-
-/// Means for transacting assets on this chain.
-pub type LocalAssetTransactor = CurrencyAdapter<
-	// Use this currency:
-	Balances,
-	// Use this currency when it is a fungible asset matching the given location or name:
-	IsConcrete<RococoLocation>,
-	// Do a simple punn to convert an AccountId32 MultiLocation into a native chain account ID:
-	LocationToAccountId,
-	// Our chain's account ID type (we can't get away without mentioning it explicitly):
-	AccountId,
->;
-
 /// This is the type we use to convert an (incoming) XCM origin into a local `Origin` instance,
 /// ready for dispatching a transaction with Xcm's `Transact`. There is an `OriginKind` which can
-/// biases the kind of local `Origin` it will become.
+/// bias the kind of local `Origin` it will become.
 pub type XcmOriginToTransactDispatchOrigin = (
 	// Sovereign account converter; this attempts to derive an `AccountId` from the origin location
 	// using `LocationToAccountId` and then turn that into the usual `Signed` origin. Useful for
 	// foreign chains who want to have a local sovereign account on this chain which they control.
-	SovereignSignedViaLocation<LocationToAccountId, Origin>,
+	SovereignSignedViaLocation<ParentIsDefault<AccountId>, Origin>,
-	// Native converter for Relay-chain (Parent) location; will converts to a `Relay` origin when
-	// recognised.
-	RelayChainAsNative<RelayChainOrigin, Origin>,
-	// Native converter for sibling Parachains; will convert to a `SiblingPara` origin when
-	// recognised.
-	SiblingParachainAsNative<cumulus_pallet_xcm::Origin, Origin>,
 	// Superuser converter for the Relay-chain (Parent) location. This will allow it to issue a
 	// transaction from the Root origin.
 	ParentAsSuperuser<Origin>,
-	// Native signed account converter; this just converts an `AccountId32` origin into a normal
-	// `Origin::Signed` origin of the same 32-byte value.
-	SignedAccountId32AsNative<RococoNetwork, Origin>,
 );
 
-parameter_types! {
+match_type! {
-	pub UnitWeightCost: Weight = 1_000;
+	pub type JustTheParent: impl Contains<MultiLocation> = { X1(Parent) };
 }
 
 parameter_types! {
-	// 1_000_000_000_000 => 1 unit of asset for 1 unit of Weight.
+	// One XCM operation is 1_000_000 weight - almost certainly a conservative estimate.
-	// TODO: Should take the actual weight price. This is just 1_000 ROC per second of weight.
+	pub UnitWeightCost: Weight = 1_000_000;
-	pub const WeightPrice: (MultiLocation, u128) = (MultiLocation::X1(Junction::Parent), 1_000);
-	pub AllowUnpaidFrom: Vec<MultiLocation> = vec![ MultiLocation::X1(Junction::Parent) ];
 }
 
-pub type Barrier = (
+pub struct NoTrader;
-	TakeWeightCredit,
+impl xcm_executor::traits::WeightTrader for NoTrader {
-	AllowTopLevelPaidExecutionFrom<All<MultiLocation>>,
+	fn new() -> Self { NoTrader }
-	AllowUnpaidExecutionFrom<IsInVec<AllowUnpaidFrom>>,	// <- Parent gets free execution
+	fn buy_weight(&mut self, _: Weight, _: xcm_executor::Assets)
-);
+		-> Result<xcm_executor::Assets, xcm::v0::Error>
+	{
+		Err(xcm::v0::Error::Unimplemented)
+	}
+}
 
 pub struct XcmConfig;
 impl Config for XcmConfig {
 	type Call = Call;
-	type XcmSender = XcmRouter;
+	type XcmSender = ();	// sending XCM not supported
-	// How to withdraw and deposit an asset.
+	type AssetTransactor = ();	// balances not supported
-	type AssetTransactor = LocalAssetTransactor;
 	type OriginConverter = XcmOriginToTransactDispatchOrigin;
-	type IsReserve = NativeAsset;
+	type IsReserve = ();	// balances not supported
-	type IsTeleporter = NativeAsset;	// <- should be enough to allow teleportation of ROC
+	type IsTeleporter = ();	// balances not supported
 	type LocationInverter = LocationInverter<Ancestry>;
-	type Barrier = Barrier;
+	type Barrier = AllowUnpaidExecutionFrom<JustTheParent>;
-	type Weigher = FixedWeightBounds<UnitWeightCost, Call>;
+	type Weigher = FixedWeightBounds<UnitWeightCost, Call>;		// balances not supported
-	type Trader = FixedRateOfConcreteFungible<WeightPrice, ()>;
+	type Trader = NoTrader;		// balances not supported
 	type ResponseHandler = ();	// Don't handle responses for now.
 }
 
 parameter_types! {
-	pub const MaxDownwardMessageWeight: Weight = MAXIMUM_BLOCK_WEIGHT / 10;
+	pub const MaxDownwardMessageWeight: Weight = MAXIMUM_BLOCK_WEIGHT / 2;
-}
-
-/// No local origins on this chain are allowed to dispatch XCM sends/executions.
-pub type LocalOriginToLocation = ();
-
-/// The means for routing XCM messages which are not for local execution into the right message
-/// queues.
-pub type XcmRouter = (
-	// Two routers - use UMP to communicate with the relay chain:
-	cumulus_primitives_utility::ParentAsUmp<ParachainSystem>,
-	// ..and XCMP to communicate with the sibling chains.
-	XcmpQueue,
-);
-
-impl pallet_xcm::Config for Runtime {
-	type Event = Event;
-	type SendXcmOrigin = EnsureXcmOrigin<Origin, LocalOriginToLocation>;
-	type XcmRouter = XcmRouter;
-	type ExecuteXcmOrigin = EnsureXcmOrigin<Origin, LocalOriginToLocation>;
-	type XcmExecuteFilter = All<(MultiLocation, xcm::v0::Xcm<Call>)>;
-	type XcmExecutor = XcmExecutor<XcmConfig>;
 }
 
 impl cumulus_pallet_xcm::Config for Runtime {
@@ -351,12 +233,6 @@ impl cumulus_pallet_xcm::Config for Runtime {
 	type MaxWeight = MaxDownwardMessageWeight;
 }
 
-impl cumulus_pallet_xcmp_queue::Config for Runtime {
-	type Event = Event;
-	type XcmExecutor = XcmExecutor<XcmConfig>;
-	type ChannelInfo = ParachainSystem;
-}
-
 construct_runtime! {
 	pub enum Runtime where
 		Block = Block,
@@ -364,20 +240,40 @@ construct_runtime! {
 		UncheckedExtrinsic = UncheckedExtrinsic,
 	{
 		System: frame_system::{Pallet, Call, Storage, Config, Event<T>},
-		Timestamp: pallet_timestamp::{Pallet, Call, Storage, Inherent},
+		ParachainSystem: cumulus_pallet_parachain_system::{Pallet, Call, Storage, Inherent, Event<T>, ValidateUnsigned},
-		Balances: pallet_balances::{Pallet, Call, Storage, Config<T>, Event<T>},
-		RandomnessCollectiveFlip: pallet_randomness_collective_flip::{Pallet, Call, Storage},
-		ParachainSystem: cumulus_pallet_parachain_system::{Pallet, Call, Storage, Inherent, Event<T>},
-		TransactionPayment: pallet_transaction_payment::{Pallet, Storage},
 		ParachainInfo: parachain_info::{Pallet, Storage, Config},
 
-		// XCM helpers.
+		// DMP handler.
-		XcmpQueue: cumulus_pallet_xcmp_queue::{Pallet, Call, Storage, Event<T>},
-		PolkadotXcm: pallet_xcm::{Pallet, Call, Storage, Event<T>, Origin},
 		CumulusXcm: cumulus_pallet_xcm::{Pallet, Call, Storage, Event<T>, Origin},
 	}
 }
 
+/// Simple implementation which fails any transaction which is signed.
+#[derive(Eq, PartialEq, Clone, Default, sp_core::RuntimeDebug, codec::Encode, codec::Decode)]
+pub struct DisallowSigned;
+impl sp_runtime::traits::SignedExtension for DisallowSigned {
+	const IDENTIFIER: &'static str = "DisallowSigned";
+	type AccountId = AccountId;
+	type Call = Call;
+	type AdditionalSigned = ();
+	type Pre = ();
+	fn additional_signed(&self)
+		-> sp_std::result::Result<(), sp_runtime::transaction_validity::TransactionValidityError>
+	{
+		Ok(())
+	}
+	fn validate(
+		&self,
+		_who: &Self::AccountId,
+		_call: &Self::Call,
+		_info: &sp_runtime::traits::DispatchInfoOf<Self::Call>,
+		_len: usize,
+	) -> TransactionValidity {
+		let i = sp_runtime::transaction_validity::InvalidTransaction::BadProof;
+		Err(sp_runtime::transaction_validity::TransactionValidityError::Invalid(i))
+	}
+}
+
 /// The address format for describing accounts.
 pub type Address = sp_runtime::MultiAddress<AccountId, ()>;
 /// Block header type as expected by this runtime.
@@ -389,14 +285,7 @@ pub type SignedBlock = generic::SignedBlock<Block>;
 /// BlockId type as expected by this runtime.
 pub type BlockId = generic::BlockId<Block>;
 /// The SignedExtension to the basic transaction logic.
-pub type SignedExtra = (
+pub type SignedExtra = DisallowSigned;
-	frame_system::CheckSpecVersion<Runtime>,
-	frame_system::CheckGenesis<Runtime>,
-	frame_system::CheckEra<Runtime>,
-	frame_system::CheckNonce<Runtime>,
-	frame_system::CheckWeight<Runtime>,
-	pallet_transaction_payment::ChargeTransactionPayment<Runtime>,
-);
 /// Unchecked extrinsic type as expected by this runtime.
 pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<Address, Call, Signature, SignedExtra>;
 /// Extrinsic type that has already been checked.
@@ -451,7 +340,7 @@ impl_runtime_apis! {
 		}
 
 		fn random_seed() -> <Block as BlockT>::Hash {
-			RandomnessCollectiveFlip::random_seed().0
+			System::parent_hash()
 		}
 	}
 
@@ -471,14 +360,12 @@ impl_runtime_apis! {
 	}
 
 	impl sp_session::SessionKeys<Block> for Runtime {
-		fn decode_session_keys(
+		fn decode_session_keys(_: Vec<u8>) -> Option<Vec<(Vec<u8>, sp_core::crypto::KeyTypeId)>> {
-			encoded: Vec<u8>,
+			Some(Vec::new())
-		) -> Option<Vec<(Vec<u8>, sp_core::crypto::KeyTypeId)>> {
-			SessionKeys::decode_into_raw_public_keys(&encoded)
 		}
 
-		fn generate_session_keys(seed: Option<Vec<u8>>) -> Vec<u8> {
+		fn generate_session_keys(_: Option<Vec<u8>>) -> Vec<u8> {
-			SessionKeys::generate(seed)
+			Vec::new()
 		}
 	}
 }

cumulus/rococo-parachains/src/chain_spec.rs

@@ -173,7 +173,6 @@ fn shell_testnet_genesis(parachain_id: ParaId) -> shell_runtime::GenesisConfig {
 				.to_vec(),
 			changes_trie_config: Default::default(),
 		},
-		pallet_balances: shell_runtime::BalancesConfig::default(),
 		parachain_info: shell_runtime::ParachainInfoConfig { parachain_id },
 	}
 }