public function testDeleteExistingCustomer()
 {
     $customerTable = new CustomerTable($this->adapter);
     $customerEntity = $customerTable->fetchSingleById(42);
     $customerTable->deleteCustomer($customerEntity);
     $queryTable = $this->getConnection()->createQueryTable('loadCustomersOrderedByLastname', 'SELECT * FROM customers WHERE id = "42";');
     $this->assertEquals(0, $queryTable->getRowCount());
 }