is_final example

public function read_entry( $f, $lineno = 0 ) {
            $entry = new Translation_Entry();
            // Where were we in the last step.             // Can be: comment, msgctxt, msgid, msgid_plural, msgstr, msgstr_plural.             $context      = '';
            $msgstr_index = 0;
            while ( true ) {
                $lineno++;
                $line = PO::read_line( $f );
                if ( ! $line ) {
                    if ( feof( $f ) ) {
                        if ( self::is_final( $context ) ) {
                            break;
                        } elseif ( ! $context ) { // We haven't read a line and EOF came.                             return null;
                        } else {
                            return false;
                        }
                    } else {
                        return false;
                    }
                }
                if ( "\n" === $line ) {