--- OptionParser::Switch#summarize(sdone, ldone, width, max, indent)
    Makes summary strings.
    :Parameters:
      : sdone
        already summarized short style options keyed hash.
      : ldone
        already summarized long style options keyed hash.
      : width
        width of left side, option part. in other word, right side,
        description part strings start at width column.
      : max
        maximum width of left side, options are filled within max columns.
      : indent
        prefix string indents each summarized lines.
      : block
        to be passed each lines(without newline).

