getJson() public static method

Gets Json String of Object Cost
public static getJson ( ) : string
return string
 /**
  * Gets Json String of Object Invoice
  * @return string
  */
 public static function getJson()
 {
     return '{"id":"TestSample","number":"TestSample","uri":"TestSample","status":"TestSample","merchant_info":' . MerchantInfoTest::getJson() . ',"billing_info":' . BillingInfoTest::getJson() . ',"shipping_info":' . ShippingInfoTest::getJson() . ',"items":' . InvoiceItemTest::getJson() . ',"invoice_date":"TestSample","payment_term":' . PaymentTermTest::getJson() . ',"discount":' . CostTest::getJson() . ',"shipping_cost":' . ShippingCostTest::getJson() . ',"custom":' . CustomAmountTest::getJson() . ',"tax_calculated_after_discount":true,"tax_inclusive":true,"terms":"TestSample","note":"TestSample","merchant_memo":"TestSample","logo_url":"http://www.google.com","total_amount":' . CurrencyTest::getJson() . ',"payments":' . PaymentDetailTest::getJson() . ',"refunds":' . RefundDetailTest::getJson() . ',"metadata":' . MetadataTest::getJson() . ',"additional_data":"TestSample"}';
 }
 /**
  * Gets Json String of Object InvoiceItem
  * @return string
  */
 public static function getJson()
 {
     return '{"name":"TestSample","description":"TestSample","quantity":"12.34","unit_price":' . CurrencyTest::getJson() . ',"tax":' . TaxTest::getJson() . ',"date":"TestSample","discount":' . CostTest::getJson() . '}';
 }
 /**
  * Gets Json String of Object TemplateData
  * @return string
  */
 public static function getJson()
 {
     return '{"merchant_info":' . MerchantInfoTest::getJson() . ',"billing_info":' . BillingInfoTest::getJson() . ',"shipping_info":' . ShippingInfoTest::getJson() . ',"items":' . InvoiceItemTest::getJson() . ',"payment_term":' . PaymentTermTest::getJson() . ',"reference":"TestSample","discount":' . CostTest::getJson() . ',"shipping_cost":' . ShippingCostTest::getJson() . ',"custom":' . CustomAmountTest::getJson() . ',"allow_partial_payment":true,"minimum_amount_due":' . CurrencyTest::getJson() . ',"tax_calculated_after_discount":true,"tax_inclusive":true,"terms":"TestSample","note":"TestSample","merchant_memo":"TestSample","logo_url":"http://www.google.com","total_amount":' . CurrencyTest::getJson() . ',"attachments":' . FileAttachmentTest::getJson() . '}';
 }
 /**
  * Gets Json String of Object InvoiceItem
  * @return string
  */
 public static function getJson()
 {
     return '{"name":"TestSample","description":"TestSample","quantity":"12.34","unit_price":' . CurrencyTest::getJson() . ',"tax":' . TaxTest::getJson() . ',"date":"TestSample","discount":' . CostTest::getJson() . ',"image_url":"http://www.google.com","unit_of_measure":"TestSample"}';
 }