public $id;
public $username;
public $password;
public $first_name;
public $last_name;


public static function find_all_users()
{

    return self::find_this_query("SELECT  *FROM users");
}


public static function find_all_user_by_id($user_id)
{

    global $database;
    $result_set = self::find_this_query("SELECT *FROM users WHERE  id='$user_id' LIMIT 1");
    $found_user = mysqli_fetch_array($result_set);
    return $found_user;
}

public static function find_this_query($sql)
{
    global $database;
    $result_set = $database->query($sql);
    $the_object_array = array();
    while ($row = mysqli_fetch_assoc($result_set)) {
        $the_object_array[] = self::instanation($row);
    }
    return $the_object_array;

}

public static function instanation($the_record)
{
    $the_object = new self;
    /*  $the_object->id=$found_user['id'];
      $the_object->username= $found_user['username'];
      $the_object->password= $found_user['password'];
      $the_object->first_name= $found_user['first_name'];
      $the_object->last_name= $found_user['last_name'];*/

    foreach ($the_record as $the_attribute => $value) {
        if ($the_object->has_the_attribute($the_attribute)) {

            $the_object->$the_attribute = $value;
        }
    }

    return $the_record;
}

private function has_the_attribute($the_attribute)
{
    $object_properties = get_object_vars($this);
    array_key_exists($the_attribute, $object_properties);

}