(declare-function article-narrow-to-head "gnus-art" ())
(declare-function gnus-article-hidden-text-p "gnus-art" (type))
(declare-function gnus-delete-wash-type "gnus-art" (type))
+(declare-function gnus-mime-buttonize-attachments-in-header
+ "gnus-art" (&optional interactive))
(defun gnus-summary-toggle-header (&optional arg)
"Show the headers if they are hidden, or hide them if they are shown.