public function getAll()
 {
     $query = "SELECT * FROM temos";
     $temos = [];
     foreach ($this->connection->query($query) as $row) {
         $tema = new Tema();
         $tema->setId($row['id']);
         $tema->setDate($row['subject_date']);
         $tema->setName($row['name']);
         $tema->setCommentCount($row['comment_count']);
         $temos[] = $tema;
     }
     return $temos;
 }