public function create($subscription, $plan, array $parameters = [])
    {
        $parameters = array_merge($parameters, compact('plan', 'subscription'));

        return $this->_post('subscription_items', $parameters);
    }
public function create($subscription, $plan, array $parameters = [])
    {
        $parameters = array_merge($parameters, compact('plan', 'subscription'));

        return $this->_post('subscription_items', $parameters);
    }
public function create ( $ subscription , $ plan , array $ parameters = [ ] ) { $ parameters = array_merge ( $ parameters , compact ( 'plan' , 'subscription' ) ) ; return $ this -> _post ( 'subscription_items' , $ parameters ) ; }
Creates a new item an existing subscription.

@param  string  $subscription
@param  string  $plan
@param  array  $parameters
@return array
Creates a new item an existing subscription .