def surround_parse(self, node, pre_char, post_char):
self.add_text(pre_char)<EOL>self.subnode_parse(node)<EOL>self.add_text(post_char)<EOL>
Parse the subnodes of a given node. Subnodes with tags in the
        `ignore` list are ignored. Prepend `pre_char` and append `post_char` to
        the output in self.pieces.