def duplicate
      _basename = basename_sans_extension
      copy = 1
      if _basename.to_s =~ /^(.*) copy (\d+)$/
        _basename = $1
        copy = $2.to_i
      end
      begin
        new_file = self.class.new(@adapter, dirname + "#{_basename} copy #{copy}#{extname}")
        copy += 1
      end while new_file.exist?
      new_file
    end
def duplicate
      _basename = basename_sans_extension
      copy = 1
      if _basename.to_s =~ /^(.*) copy (\d+)$/
        _basename = $1
        copy = $2.to_i
      end
      begin
        new_file = self.class.new(@adapter, dirname + "#{_basename} copy #{copy}#{extname}")
        copy += 1
      end while new_file.exist?
      new_file
    end
of unique