frames.php
protected function getPublicNameFromIndex($subject)
    {
        foreach ($this->names as $name => $index) {
            if ($subject == $index) {
                return $name;
            }
        }

        return $subject + 1;
    }
protected function getPublicNameFromIndex($subject)
    {
        foreach ($this->names as $name => $index) {
            if ($subject == $index) {
                return $name;
            }
        }

        return $subject + 1;
    }
Turns an internal array index into the frames list,
into a public name, or if none, then a one offset index.

@param int $subject    Internal index.

@return integer/string     Public name.