docs: def init_config(self, app):
          """Initialize configuration."""
          for k in dir(config):
              if k.startswith('JSONSCHEMAS_'):
                  app.config.setdefault(k, getattr(config, k))
  
          host_setting = app.config['JSONSCHEMAS_HOST']
          if not host_setting or host_setting == 'localhost':
              app.logger.warning('JSONSCHEMAS_HOST is set to {0}'.format(
                  host_setting))