def report
      dups = duplicates
      s = "Base dir: #{@dirname}\n"
      s += "Nr. file: #{size}"
      if dups.size > 0
        s+= " (duplicates #{dups.size})"
      end
      s += "\nBytes: #{bytes.with_separator}"
      s
    end
def report
      dups = duplicates
      s = "Base dir: #{@dirname}\n"
      s += "Nr. file: #{size}"
      if dups.size > 0
        s+= " (duplicates #{dups.size})"
      end
      s += "\nBytes: #{bytes.with_separator}"
      s
    end
simple report with essential information about this catalog
 @return [String] report