private AuthenticationFailureStatus getAuthenticationFailure(String address) {

        AuthenticationFailureStatus status = failures.get(address,
                (addr) -> new AuthenticationFailureStatus(maxAttempts, banDuration));

        status.notifyFailed();
        return status;

    }
Reports that the given address has just failed to authenticate and
returns the AuthenticationFailureStatus that represents that failure. If
the address isn't already being tracked, it will begin being tracked as
of this call. If the address is already tracked, the returned
AuthenticationFailureStatus will represent past authentication failures,
as well.

@param address
    The address that has failed to authenticate.

@return
    An AuthenticationFailureStatus that represents this latest
    authentication failure for the given address, as well as any past
    failures.
extensions/guacamole-auth-ban/src/main/java/org/apache/guacamole/auth/ban/status/InMemoryAuthenticationFailureTracker.java