public function discount()
    {
        return $this->formatAmount($this->invoice->subtotal + $this->invoice->tax - $this->invoice->total);
    }
public function discount()
    {
        return $this->formatAmount($this->invoice->subtotal + $this->invoice->tax - $this->invoice->total);
    }
public function discount ( ) { return $ this -> formatAmount ( $ this -> invoice -> subtotal + $ this -> invoice -> tax - $ this -> invoice -> total ) ; }
Get the discount amount.

@return string
Get the discount amount .