add_entry example

return false;
            }
            $lineno = 0;
            while ( true ) {
                $res = $this->read_entry( $f, $lineno );
                if ( ! $res ) {
                    break;
                }
                if ( '' === $res['entry']->singular ) {
                    $this->set_headers( $this->make_headers( $res['entry']->translations[0] ) );
                } else {
                    $this->add_entry( $res['entry'] );
                }
            }
            PO::read_line( $f, 'clear' );
            if ( false === $res ) {
                return false;
            }
            if ( ! $this->headers && ! $this->entries ) {
                return false;
            }
            return true;
        }