question: private void updateDetailData ( ) { final long start = mLeftPosition ; final long end = mRightPosition ; final long now = mCurrentTime ; final Context context = getContext ( ) ; NetworkStatsHistory . Entry originalEntry = mOriginalNetworkStatsHistory . getValues ( start , end , now , null ) ; final long originalTotalBytes = originalEntry . rxBytes ; mOriginalTotalPhrase = Formatter . formatFileSize ( context , originalTotalBytes ) ; NetworkStatsHistory . Entry compressedEntry = mReceivedNetworkStatsHistory . getValues ( start , end , now , null ) ; final long compressedTotalBytes = compressedEntry . rxBytes ; mReceivedTotalPhrase = Formatter . formatFileSize ( context , compressedTotalBytes ) ; float percentage = 0.0f ; if ( originalTotalBytes > 0L && originalTotalBytes > compressedTotalBytes ) { percentage = ( originalTotalBytes - compressedTotalBytes ) / ( float ) originalTotalBytes ; } mPercentReductionPhrase = String . format ( "%.0f%%" , 100.0 * percentage ) ; mStartDatePhrase = formatDate ( context , start ) ; mEndDatePhrase = formatDate ( context , end ) ; }
target:  Update data reduction statistics whenever the chart's inspection range changes. In particular, this creates strings describing the total original size of all data received over the date range, the total size of all data received (after compression), the percent data reduction and the range of dates over which these statistics apply.