lib.rs

			if l.id == id {
				new_lock.take().map(|nl| {
					BalanceLock {
						id: l.id,
						amount: l.amount.max(nl.amount),
						until: l.until.max(nl.until),
						reasons: l.reasons | nl.reasons,
					}
				})
			} else if l.until > now {
				Some(l)
			} else {
				None
			}).collect::<Vec<_>>();
		if let Some(lock) = new_lock {
			locks.push(lock)
		}
		<Locks<T, I>>::insert(who, locks);
	}

	fn remove_lock(
		id: LockIdentifier,
		who: &T::AccountId,
	) {
		let now = <system::Module<T>>::block_number();
		let locks = Self::locks(who).into_iter().filter_map(|l|
			if l.until > now && l.id != id {
				Some(l)
			} else {
				None
			}).collect::<Vec<_>>();
		<Locks<T, I>>::insert(who, locks);
	}
}

impl<T: Trait<I>, I: Instance> MakePayment<T::AccountId> for Module<T, I> {
	fn make_payment(transactor: &T::AccountId, encoded_len: usize) -> Result {
		let encoded_len = <T::Balance as As<u64>>::sa(encoded_len as u64);
		let transaction_fee = Self::transaction_base_fee() + Self::transaction_byte_fee() * encoded_len;
		let imbalance = Self::withdraw(
			transactor,
			transaction_fee,
			WithdrawReason::TransactionPayment,
			ExistenceRequirement::KeepAlive
		)?;
		T::TransactionPayment::on_unbalanced(imbalance);
		Ok(())
	}
}

impl<T: Trait<I>, I: Instance> IsDeadAccount<T::AccountId> for Module<T, I>
where
	T::Balance: MaybeSerializeDebug
{
	fn is_dead_account(who: &T::AccountId) -> bool {
		Self::total_balance(who).is_zero()
	}
}