OverwriteModeEnum
Specifies the mode for importing files.
 
                
Append = 0
Import all files, even if this causes duplication. Faster than Append/Overlay mode.
 
AppendOverlay = 2
Import all files.  Those that are duplicates will be updated to the new version of the file.
 
Overlay = 1
Update all files if new versions are made available by the import.