docs: def render(self, template_name, **kw):
          '''
          Given a template name and template vars.
          Searches a template file based on engine set, and renders it 
          with corresponding engine.
          Returns a string.
          '''
          logger.debug('Rendering template "%s"', template_name)
          vars = self.globs.copy()
          vars.update(kw)
          resolved_name, engine = self.resolve(template_name)
          return engine.render(resolved_name, **vars)