Returns pointer to the user data associated with the given local context item. The size of the data area depends on the "dataSize" argument used when allocating this item. If the pointer to the item given (localItem) is NULL, this function returns NULL.
INPUTS
localItem
pointer to local context item or NULL.
RESULT
data
pointer to user data area or NULL if localItem is NULL.
BUGS
Currently, there is no way to determine the size of the user data area; you have to 'know'.