code: function (collection, options, callback) {
          if (!options.outputVersion || !semver.valid(options.outputVersion, true)) {
              return callback(new Error('Output version not specified or invalid: ' + options.outputVersion));
          }
          if (!options.inputVersion || !semver.valid(options.inputVersion, true)) {
              return callback(new Error('Input version not specified or invalid: ' + options.inputVersion));
          }
  
          return converter.convert(collection, options, callback);
      }
docs: Converts a Collection between different versions, based on the given input.
  
  @param {Object} collection - The collection object to be converted.
  @param {Object} options - The set of conversion options.
  @param {String} options.outputVersion - The version to convert to.
  @param {String} options.inputVersion - The version to convert from.
  @param {Function} callback - The function invoked to mark the completion of the conversion process.