def partition(&block)       # :nodoc:
      resolve
      result = @items.partition(&block)
      [
        FileList.new.import(result[0]),
        FileList.new.import(result[1]),
      ]
    end
def partition(&block)       # :nodoc:
      resolve
      result = @items.partition(&block)
      [
        FileList.new.import(result[0]),
        FileList.new.import(result[1]),
      ]
    end
FileList version of partition.  Needed because the nested arrays should
 be FileLists in this version.