def diffReport(newString, oldString)
      i = 0
      minLength = [newString.length, oldString.length].min
      while i<minLength and newString[i] == oldString[i] do
        i += 1
      end
      diffPos = i
      newStringEndPos = [diffPos+20,newString.length].min
      oldStringEndPos = [diffPos+20, newString.length].min
      startPos = [0, diffPos-10].max
      "Different from position #{diffPos}: \n  #{newString[startPos...newStringEndPos].inspect}\n !=\n  #{oldString[startPos...newStringEndPos].inspect}"
    end
def diffReport(newString, oldString)
      i = 0
      minLength = [newString.length, oldString.length].min
      while i<minLength and newString[i] == oldString[i] do
        i += 1
      end
      diffPos = i
      newStringEndPos = [diffPos+20,newString.length].min
      oldStringEndPos = [diffPos+20, newString.length].min
      startPos = [0, diffPos-10].max
      "Different from position #{diffPos}: \n  #{newString[startPos...newStringEndPos].inspect}\n !=\n  #{oldString[startPos...newStringEndPos].inspect}"
    end
Report the difference between two strings (that should be the same)