public function addInvoice(InvoiceInterface $invoice)
    {
        if (!$this->invoices->contains($invoice)) {
            $this->invoices->add($invoice);
        }

        return $this;
    }
public function addInvoice(InvoiceInterface $invoice)
    {
        if (!$this->invoices->contains($invoice)) {
            $this->invoices->add($invoice);
        }

        return $this;
    }
public function addInvoice ( InvoiceInterface $ invoice ) { if ( ! $ this -> invoices -> contains ( $ invoice ) ) { $ this -> invoices -> add ( $ invoice ) ; } return $ this ; }
Adds the invoice.

@param InvoiceInterface $invoice

@return Notify
Adds the invoice .