void delete(int version) throws IOException {
		synchronized (fileSystem) {
			if (fileSystem.isReadOnly()) {
				throw new ReadOnlyException(
					"delete(version) permitted within writeable project only");
			}
			if (versionedFolderItem == null) {
				throw new IOException(name + " is not versioned");
			}
			if (folderItem != null && folderItem.getCheckoutVersion() == version) {
				throw new FileInUseException(name + " version " + version + " is checked-out");
			}
			versionedFolderItem.delete(version, ClientUtil.getUserName());
		}
	}
Deletes a specific version of a file from the versioned filesystem.  
@param version specific version to be deleted.  The version must either
be the oldest or latest, or -1 which will attempt to remove all versions.
When deleting the latest version, this method could take a long time
to return since the previous version must be reconstructed within the
versioned filesystem.
@throws IOException if an IO error occurs, including the inability 
to delete a version because this item is checked-out, the user does
not have permission, or the specified version is not the oldest or
latest.
Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFileData.java