API ScrollingMessageFrame SetInsertMode

Set whether new messages add to the top or bottom of a ScrollingMessageFrame.
 ScrollingMessageFrame:SetInsertMode("mode")
----
;Arguments
:String
:;mode : "top" or "bottom"
----
;Returns
:;nil
----
;Example
 DEFAULT_CHAT_FRAME:SetInsertMode("top")
 DEFAULT_CHAT_FRAME:Clear()
;Result
 New messages added to the DEFAULT_CHAT_FRAME are inserted at the top and scrolls the old messages down.
==Details==
:A SetInsertMode to a ScrollingMessageFrame that already contains text appears to have no effect until it is cleared.
:The usage error and a call to API ScrollingMessageFrame GetInsertMode seem to insist on using all-caps "TOP" or "BOTTOM", but only lower case "top" or "bottom" appear to work.