GetAlreadyExistsMessage returns a string that can be returned back to the user as a feedback message to tell them that an entry with that value already exists.

GetDoesNotExistMessage returns a string that can be returned back to the user as a feedback message to tell them that an entry with that value does not exist.

GetIncorrectMessage returns a string that can be returned back to the user as a feedback message to tell them that the value they entered is incorrect.

GetInvalidTokenMessage returns a string that can be returned back to the user as a feedback message to tell them that the value they entered is not a valid token.

Validate takes a struct as an argument and runs some validation checks on it that are specified on that struct in the tags.