XWG

It is expected that invocations of the form `transfer(recipient, amount)` succeed and return `true` if * The address in `recipient` is not the zero address, * `amount` does not exceed the balance of address `msg.sender`, * transferring `amount` to the address `recipient` does not lead to an overflow of the recipient's balance, and * the supplied gas suffices to complete the call. Nevertheless, the `transfer` function of `XWGToken` fails in some of those admissible cases.

It is expected that invocations of the form `transfer(recipient, amount)` where the address in `recipient` equals the address in `msg.sender` (i.e. self-transfers) succeed and return `true` if * The value in `amount` does not exceed the balance of `msg.sender` and * the supplied gas suffices to complete the call. Nevertheless, the `transfer` function of `XWGToken` fails in some of those admissible cases.

It is expected that invocations of `transferFrom(from, dest, amount)` succeed and return `true` if * the value of `amount` does not exceed the balance of address `from`, * the value of `amount` does not exceed the allowance of `msg.sender` for address `from`, * transferring a value of `amount` to the address in `dest` does not lead to an overflow of the recipient's balance, and * the supplied gas suffices to complete the call. Nevertheless, the `transferFrom` function of `XWGToken` fails in some of those admissible cases.

It is expected that invocations of `transferFrom(from, dest, amount)` where the address in `dest` equals the address in `from` (i.e. self-transfers) succeed and return `true` if: * The value of `amount` does not exceed the balance of address `from`, * the value of `amount` does not exceed the allowance of `msg.sender` for address `from`, and * the supplied gas suffices to complete the call. Nevertheless, the `transferFrom` function of `XWGToken` fails for some self-transfers in these admissible cases.

`public` functions that are never called by the contract could be declared as `external`. `external` functions are more efficient than `public` functions.

The linked variables assigned in the constructor can be declared as `immutable`. Immutable state variables can be assigned during contract creation but will remain constant throughout the lifetime of a deployed contract. A big advantage of immutable variables is that reading them is significantly cheaper than reading from regular state variables since they will not be stored in storage.