public function trialDays($trialDays = null)
    {
        if (is_null($trialDays)) {
            return $this->trialDays;
        }

        $this->trialDays = $trialDays;

        return $this;
    }
public function trialDays($trialDays = null)
    {
        if (is_null($trialDays)) {
            return $this->trialDays;
        }

        $this->trialDays = $trialDays;

        return $this;
    }
public function trialDays ( $ trialDays = null ) { if ( is_null ( $ trialDays ) ) { return $ this -> trialDays ; } $ this -> trialDays = $ trialDays ; return $ this ; }
Specify the number of trial days the plan receives.

@param  int  $days
@return $this
Specify the number of trial days the plan receives .