code: def _check_config(self):
          
          required_data = ['creation_date',
                           'author',
                           'status',
                           'lang',
                           'tags',
                           'title',
                           'slug',
                           'theme',
                           'template',
                           'page_id']
          isok = True
          # exclude some statements from coverage analysis. I would need to
          # refactor how the config is loaded/handled etc. It's not worth
          # to do that now. Maybe when I change yaml for the markdwn extension.
          for e in self._config.keys():
              if not e in required_data: # pragma: no cover
                  print "The configuration in page '" + \
                        self._slug + "' is corrupt."
                  isok = False
              # check that the theme and template exist, even if they're default.
          (pthemedir, ptemplatefname) = self._theme_and_template_fp()
          if not os.path.isdir(pthemedir): # pragma: no cover
              print "Theme " + self._config['theme'][0] + \
                    " specified in page '" + \
                    self._slug + "' does not exist."
              isok = False
          if not os.path.isfile(ptemplatefname): # pragma: no cover
              print "Template " + self._config['template'][0] + \
                    " specified in page '" + self._slug + \
                    "' does not exist."
              isok = False
          return isok
docs: Verify that the configuration is correct.