protected function setupTaxDetails(array $taxDetails) { $taxDetailsMock = $this->getMockBuilder('\\Magento\\Tax\\Api\\Data\\GrandTotalDetailsInterface')->getMock(); $this->detailsFactoryMock->expects($this->once())->method('create')->willReturn($taxDetailsMock); $taxDetailsMock->expects($this->once())->method('setAmount')->with($taxDetails['amount'])->willReturnSelf(); $taxDetailsMock->expects($this->once())->method('setRates')->with($taxDetails['rates'])->willReturnSelf(); $taxDetailsMock->expects($this->once())->method('setGroupId')->with(1)->willReturnSelf(); return $taxDetailsMock; }