/**
* Render a template using the theme engine.
*
+ * It is the theme engine's responsibility to escape variables. The only
+ * exception is if a variable implements
+ * \Drupal\Component\Render\MarkupInterface. Drupal is inherently unsafe if
+ * other variables are not escaped. The helper function
+ * theme_render_and_autoescape() may be used for this.
+ *
* @param string $template_file
* The path (relative to the Drupal root directory) to the template to be
* rendered including its extension in the format 'path/to/TEMPLATE_NAME.EXT'.