public function test_vertical_fleet_deployment()
 {
     $fleet = new Fleet();
     $fleet->addShip(new Destroyer('d1'));
     $fleet->setDirection('vertical');
     $fleet->setRow('a');
     $fleet->setColumn(1);
     $fleet->deploy();
     $grid = $fleet->getGridCoordinates();
     $this->assertEquals('d1', $grid['a'][1], 'Expected d1 got ' . $grid['a'][1]);
     $this->assertEquals('d1', $grid['b'][1], 'Expected d1 got ' . $grid['b'][1]);
     $this->assertEquals('d1', $grid['c'][1], 'Expected d1 got ' . $grid['c'][1]);
     $this->assertEquals('d1', $grid['d'][1], 'Expected d1 got ' . $grid['d'][1]);
 }