renderItems example

if (is_array($value)) {
            $value = (string) $this->getRenderer()->render($value);
          }
          $this->last_render = $value;
          $this->original_value = $this->last_render;

          $alter = $item + $this->options['alter'];
          $alter['phase'] = static::RENDER_TEXT_PHASE_SINGLE_ITEM;
          $items[] = $this->renderText($alter);
        }

        $value = $this->renderItems($items);
      }
      else {
        $alter = ['phase' => static::RENDER_TEXT_PHASE_COMPLETELY] + $this->options['alter'];
        $value = $this->renderText($alter);
      }

      if (is_array($value)) {
        $value = $this->getRenderer()->render($value);
      }
      // This happens here so that renderAsLink can get the unaltered value of       // this field as a token rather than the altered value.