$p->get_token
           This method will return the next token found in the HTML document, or "undef" at the
           end of the document.  The token is returned as an array reference.  The first element
           of the array will be a string denoting the type of this token: "S" for start tag, "E"
           for end tag, "T" for text, "C" for comment, "D" for declaration, and "PI" for process
           instructions.  The rest of the token array depend on the type like this:

             ["S",  $tag, $attr, $attrseq, $text]
             ["E",  $tag, $text]
             ["T",  $text, $is_data]
             ["C",  $text]
             ["D",  $text]
             ["PI", $token0, $text]