setUsername and setPassword, undefined variable $options

This is the current function:

function setUsername($username){
    $this->_options['username'] = sanitize_text_field($username);
    update_option( 'addthis_settings', $options);
}

function setPassword($password){
    $this->_options['password'] = sanitize_text_field($password);
    update_option( 'addthis_settings', $options);
}

It should be:

function setUsername($username){
    $this->_options['username'] = sanitize_text_field($username);
    update_option( 'addthis_settings', $this->_options);
}

function setPassword($password){
    $this->_options['password'] = sanitize_text_field($password);
    update_option( 'addthis_settings', $this->_options);
}

https://wordpress.org/plugins/addthis/