public function testSetAndGetConection()
 {
     $book = new Book($this->conn);
     $this->assertSame($this->conn, $book->getConnection());
     $conn = $this->getMockBuilder('Doctrine\\DBAL\\Connection')->disableOriginalConstructor()->getMock();
     $this->assertSame($book, $book->setConnection($conn));
     $this->assertSame($conn, $book->getConnection());
 }