Theme_My_Login_Action::get_slug()

public function get_slug() {
    /**
     * Filter the action slug.
     *
     * @since 7.0
     *
     * @param string $slug The action slug.
     * @param string $name The action name.
     */
    return apply_filters( 'tml_get_action_slug', $this->slug, $this->get_name() );
}

View src/includes/class-theme-my-login-action.php, line 301 on GitHub