# File lib/CharDistributionAnalysis.rb, line 232
        def get_order(aStr)
            # for euc-JP encoding, we are interested 
            #   first  byte range: 0xa0 -- 0xfe
            #   second byte range: 0xa1 -- 0xfe
            # no validation needed here. State machine has done that
            if aStr[0] >= 0xA0
                return 94 * (aStr[0] - 0xA1) + aStr[1] - 0xa1
            else
                return -1
            end
        end