Multi byte character support (emojis, etc) in file names

Hello, 

Sorry if I've missed something obvious here, but I'm trying to work out if the Box API supports uploading files with 4 and 6 byte characters in the file name (e.g. 𩸽 or 😀) and I can't find a definitive answer. It doesn't seem to work for me using the Java SDK (BoxFolder.uploadFile()). 

Thanks a lot.