code: @Override
      public void rollback(final Xid _xid)
          throws XAException
      {
          if (VFSStoreResource.LOG.isDebugEnabled())  {
              VFSStoreResource.LOG.debug("rollback (xid = " + _xid + ")");
          }
          try {
              final FileObject tmpFile = this.manager.resolveFile(this.manager.getBaseFile(),
                      this.storeFileName + VFSStoreResource.EXTENSION_TEMP);
              if (tmpFile.exists()) {
                  tmpFile.delete();
              }
          } catch (final FileSystemException e)  {
              VFSStoreResource.LOG.error("transaction rollback fails for " + _xid, e);
              final XAException xa = new XAException(XAException.XA_RBCOMMFAIL);
              xa.initCause(e);
              throw xa;
          }
      }
docs: If the file written in the virtual file system must be rolled back, only
  the created temporary file (created from method {@link #write}) is
  deleted.
  
  @param _xid      global transaction identifier (not used, because each
  file with the file id gets a new VFS store resource
  instance)
  @throws XAException if any exception occurs (catch on
  {@link java.lang.Throwable})