A cross-platform interface that supports cache for tree item 

 @status UNDER_REVIEW
[scriptable, uuid(cc742da2-9c25-4d04-96cd-da407d676c6d)]
interface nsIAccessibleTreeCache : nsISupports

Methods

 Get tree item from cache according to row and column, create if doesn't exist in cache
 "aColumn" can be nsnull
[noscript] nsIAccessible getCachedTreeitemAccessible(in PRInt32 aRow, in nsITreeColumn aColumn)