Info-speedbar-hierarchy-buttons
Info-speedbar-hierarchy-buttons is a compiled Lisp function in `info.el
'.
(Info-speedbar-hierarchy-buttons DIRECTORY DEPTH &optional NODE)
Display an Info directory hierarchy in speedbar.
DIRECTORY is the current directory in the attached frame.
DEPTH is the current indentation depth.
NODE is an optional argument that is used to represent the
specific node to expand.