old_contents: define(['Format', 'formats/byExtension'], function(Format, formatsByExtension) {
  
    'use strict';
    
    const RECORD_FMT = Format('iso-9660/chunk', {which:'file'});
    
    return {
      split: function split(segment, entries) {
        var recordSegment = (segment.format.parameters['record-segment'] || '').match(/^\s*(\d+)\s*,\s*(\d+)\s*$/);
        if (!recordSegment) {
          return Promise.reject('missing or invalid record-segment parameter');
        }
        recordSegment = segment.getSegment(RECORD_FMT, +recordSegment[1], +recordSegment[2]);
        entries.add(recordSegment);
        return recordSegment.getStruct().then(function(record) {
          var ext = record.name.match(/\.([^\.]+)$/);
          ext = ext ? ext[1].toString() : '';
          var dataFormat = formatsByExtension[ext] || Format.generic;
          var dataSegment = (segment.format.parameters['data-segment'] || '').match(/^\s*(\d+)\s*,\s*(\d+)\s*$/);
          if (!dataSegment) {
            return Promise.reject('missing or invalid data-segment parameter');
          }
          dataSegment = segment.getSegment(dataFormat, +dataSegment[1], +dataSegment[2]);
          entries.add(dataSegment);
        });
      },
      getDisplayName: function(segment) {
        return segment.split(RECORD_FMT).then(function(records) {
          if (records.length === 0) {
            return Promise.reject('split failed to find info record');
          }
          return records[0].getStruct().then(function(record) {
            return record.name;
          });
        });
      },
      getTimestamp: function(segment) {
        return segment.split(RECORD_FMT).then(function(records) {
          if (records.length === 0) {
            return Promise.reject('split failed to find info record');
          }
          return records[0].getStruct().then(function(record) {
            return record.modifiedAt || record.createdAt;
          });
        });
      },
    };
  
  });
  
new_contents: define(['Format', 'formats/byExtension'], function(Format, formatsByExtension) {
  
    'use strict';
    
    const RECORD_FMT = Format('iso-9660/chunk', {which:'file'});
    
    return {
      split: function split(segment, entries) {
        var recordSegment = (segment.format.parameters['record-segment'] || '').match(/^\s*(\d+)\s*,\s*(\d+)\s*$/);
        if (!recordSegment) {
          return Promise.reject('missing or invalid record-segment parameter');
        }
        recordSegment = segment.getSegment(RECORD_FMT, +recordSegment[1], +recordSegment[2]);
        entries.add(recordSegment);
        return recordSegment.getStruct().then(function(record) {
          var ext = record.name.match(/\.([^\.]+)$/);
          ext = ext ? ext[1].toLowerCase() : '';
          var dataFormat = formatsByExtension[ext] || Format.generic;
          var dataSegment = (segment.format.parameters['data-segment'] || '').match(/^\s*(\d+)\s*,\s*(\d+)\s*$/);
          if (!dataSegment) {
            return Promise.reject('missing or invalid data-segment parameter');
          }
          dataSegment = segment.getSegment(dataFormat, +dataSegment[1], +dataSegment[2]);
          entries.add(dataSegment);
        });
      },
      getDisplayName: function(segment) {
        return segment.split(RECORD_FMT).then(function(records) {
          if (records.length === 0) {
            return Promise.reject('split failed to find info record');
          }
          return records[0].getStruct().then(function(record) {
            return record.name;
          });
        });
      },
      getTimestamp: function(segment) {
        return segment.split(RECORD_FMT).then(function(records) {
          if (records.length === 0) {
            return Promise.reject('split failed to find info record');
          }
          return records[0].getStruct().then(function(record) {
            return record.modifiedAt || record.createdAt;
          });
        });
      },
    };
  
  });
  
subject: Fix wrong method used