[Pharo-project] Extracting a ZipArchive in 2.0

Hi, I want to extract a ZipArchive in Pharo 2.0, as the title says. I'm trying to do it with this: zipArchive extractAllTo: aDirectory informing: bar overwrite: false I'm trying the new file system but my problem is that ZipArchiveMember calls a method called "assureExistence", which does not exist... anywhere. Has anyone experience something like this? Thanks, Vanessa.