@SuppressWarnings({"UnusedDeclaration"})
    public void setAuthenticationListeners(Collection<AuthenticationListener> listeners) {
        if (listeners == null) {
            this.listeners = new ArrayList<AuthenticationListener>();
        } else {
            this.listeners = listeners;
        }
    }
Sets the {@link AuthenticationListener AuthenticationListener}s that should be notified during authentication
attempts.

@param listeners one or more {@code AuthenticationListener}s that should be notified due to an
                 authentication attempt.
core/src/main/java/org/apache/shiro/authc/AbstractAuthenticator.java