/**
  * @return void
  */
 public function testClean()
 {
     $eventMock = $this->getMockBuilder('Magento\\Reports\\Model\\Event')->disableOriginalConstructor()->getMock();
     $selectMock = $this->getMockBuilder('Magento\\Framework\\DB\\Select')->disableOriginalConstructor()->setMethods(['select', 'from', 'joinLeft', 'where', 'limit', 'fetchCol'])->getMock();
     $this->connectionMock->expects($this->at(1))->method('fetchCol')->willReturn(1);
     $this->connectionMock->expects($this->any())->method('delete');
     $this->connectionMock->expects($this->any())->method('select')->willReturn($selectMock);
     $selectMock->expects($this->any())->method('from')->willReturnSelf();
     $selectMock->expects($this->any())->method('joinLeft')->willReturnSelf();
     $selectMock->expects($this->any())->method('where')->willReturnSelf();
     $selectMock->expects($this->any())->method('limit')->willReturnSelf();
     $this->event->clean($eventMock);
 }