code: public function assign($name, $value)
      {
          try {
              if (isset($this->assign[$name])) {
                  throw new ViewException('You can\'t assign "' . $name . '" in Twig');
              }
  
              $assign = $this->assign[$name] = $value;
          } catch (ViewException $e) {
              echo $e->getMessage() . '<br />
                  File: ' . $e->getFile() . '<br />
                  Code line: ' . $e->getLine() . '<br />
                  Trace: ' . $e->getTraceAsString();
              exit();
          }
  
          return $assign;
      }
docs: Set the var to the template.
  
  @param string $name
  @param string $value
  
  @return mixed