I was writing a function in a class. NetBeans IDE code completion was not recognizing a query result variable. In procedural style mysqli NetBeans had no problem with this.
The class is a singleton that extends mysqli. The function is

public function get_wisher_id_by_name($name) {
        $name = $this->real_escape_string($name);
        $result = $this->query("SELECT id FROM wishers WHERE name = '"
                        . $name . "'");

        if ($result->num_rows > 0)
            return $result->data_seek(0);
        else
            return null;
        $result->free;
}

The problem is with the $result variable. I started to type $res but nothing showed in cc, not even when I hit ctrl-shift. (See attached screenshot, variable-cc-failure)

When I typed in $result-> manually, again no code completion for the mysqli_result::x functions. (See attached screenshot, function-cc-failure)

The manually-entered code runs without problem.