WC_Shipping_Method::get_instance_option PHP Method

    public function get_instance_option($key, $empty_value = null)
    {
        if (empty($this->instance_settings)) {
            $this->init_instance_settings();
        }
        // Get option default if unset.
        if (!isset($this->instance_settings[$key])) {
            $form_fields = $this->get_instance_form_fields();
            $this->instance_settings[$key] = $this->get_field_default($form_fields[$key]);
        }
        if (!is_null($empty_value) && '' === $this->instance_settings[$key]) {
            $this->instance_settings[$key] = $empty_value;
        }
        return $this->instance_settings[$key];
    }