         $designMock = $this->getMockBuilder(\Magento\Framework\View\DesignInterface::class)             ->disableOriginalConstructor()             ->getMock();         $this->objectManagerMock->expects($this->once())             ->method('get')             ->with(\Magento\Framework\View\DesignInterface::class)             ->willReturn($designMock);         $designMock->expects($this->once())             ->method('setArea')             ->with($this->areaCode)             ->willReturnSelf();         $designMock->expects($this->once())             ->method('setDefaultDesignTheme');         $this->object