NewAuthenticationInfo method creates an `AuthenticationInfo` instance with zero values.

ErrAuthenticationFailed error is returned when user authentication fails; such as subject password doesn't match, is-locked or is-expired.

ErrAuthenticatorIsNil error is returned when given authenticator is nil.

ErrPrincipalIsNil error is returned when given principal provider is nil.

ErrSubjectNotExists error is returned when Subject is not exists in the application datasource.

AuthenticationInfo represents a Subject's (aka user's) stored account information relevant to the authentication/log-in process only.

AuthenticationToken is an account's principals and supporting credentials submitted by a user during an authentication attempt.

Principal struct holds the principal associated with a corresponding Subject.

Authenticator interface is used to provide authentication information of application during a login.

PrincipalProvider interface is implemented to provide Subject's principals where authentication is done third party, for e.g.