(when (string-match "^\\(#+\\)[ \t]*" header-line)
(let* ((level (length (match-string 1 header-line)))
(header (substring header-line (match-end 0)))
(when (string-match "^\\(#+\\)[ \t]*" header-line)
(let* ((level (length (match-string 1 header-line)))
(header (substring header-line (match-end 0)))