docs: def _replace(self, url):
          """
          Change URLs with absolute paths so they are rooted at the correct
          location.
          """
          segments = url.split('/')
          if segments[0] == '':
              root = self.rootURL(self.request)
              if segments[1] == 'Mantissa':
                  root = root.child('static').child('mantissa-base')
                  segments = segments[2:]
              elif segments[1] in self.installedOfferingNames:
                  root = root.child('static').child(segments[1])
                  segments = segments[2:]
              for seg in segments:
                  root = root.child(seg)
              return str(root)
          return url