Bluz\Db\Db::fetchOne PHP Method

    public function fetchOne($sql, $params = [])
    {
        $stmt = $this->prepare($sql, $params);
        $result = $stmt->fetch(\PDO::FETCH_COLUMN);
        $this->ok();
        return $result;
    }

 /**
  * fetchOne
  */
 public function testFetchOne()
 {
     $result = $this->db->fetchOne("SELECT COUNT(*) FROM test");
     $this->assertEquals(42, $result);
 }