class_docstr: Represents a content.
  
  :param content: the string to parse, containing the original content.
  :param metadata: the metadata associated to this page (optional).
  :param settings: the settings dictionary (optional).
  :param source_path: The location of the source of this content (if any).
  :param context: The shared context between generators.
docstr: Update the content attribute.
  
  Change all the relative paths of the content to relative paths
  suitable for the output content.
  
  :param content: content resource that will be passed to the templates.
  :param siteurl: siteurl which is locally generated by the writer in
                  case of RELATIVE_URLS.
docstr_tok: ["Update","the","content","attribute",".","Change","all","the","relative","paths","of","the","content","to","relative","paths","suitable","for","the","output","content",".",":","param","content",":","content","resource","that","will","be","passed","to","the","templates",".",":","param","siteurl",":","siteurl","which","is","locally","generated","by","the","writer","in","case","of","RELATIVE_URLS","."]
code: def _update_content(self, content, siteurl):
      """Update the content attribute.
  
      Change all the relative paths of the content to relative paths
      suitable for the output content.
  
      :param content: content resource that will be passed to the templates.
      :param siteurl: siteurl which is locally generated by the writer in
                      case of RELATIVE_URLS.
      """
      if not content:
          return content
  
      hrefs = self._get_intrasite_link_regex()
      return hrefs.sub(
          lambda m: self._link_replacer(siteurl, m), content
      )
  
imports: import copy
  import datetime
  import locale
  import logging
  import os
  import re
  from datetime import timezone
  from html import unescape
  from urllib.parse import unquote, urljoin, urlparse, urlunparse
  from pelican.plugins import signals
  from pelican.settings import DEFAULT_CONFIG
  from pelican.utils import deprecated_attribute, memoized, path_to_url, posixize_path, sanitised_join, set_date_tzinfo, slugify, truncate_html_words
  from pelican.urlwrappers import Author, Category, Tag, URLWrapper
label_desc: Use image node_id 13 for calling the Content obj's underlying member method code with example usage: obj._update_content(content, siteurl) and returns: hrefs, content