   performXML: (fileContent, callback) ->
     xmlHelpers.xmlTransform xmlHelpers.xmlFix(fileContent), (err, result) =>
       if err
-        @returnResult false, 'Error on parsing XML: ' + err, callback
+        @returnResult false, "Error on parsing XML: #{err}", callback
       else
         @ensureChannelByKey(@rest, CHANNEL_KEY, CHANNEL_ROLES).then (channel) =>
           stocks = @_mapStockFromXML result.root, channel.id

      header = data[0]
      stocks = @_mapStockFromCSV _.rest data
      @_perform stocks, callback

  _perform: (stocks, callback) ->
    console.log 'Stock entries to process: ', _.size(stocks)

      @initMatcher(queryString).then (existingEntry) =>
        console.log "Query for sku '#{msg.body.SKU}' result: %j", existingEntry
        if msg.body.CHANNEL_KEY
          @ensureChannelByKey(@rest, msg.body.CHANNEL_KEY, CHANNEL_ROLES)
          .then (channel) =>
            @createOrUpdate([@createInventoryEntry(msg.body.SKU, msg.body.QUANTITY, msg.body.EXPECTED_DELIVERY, channel.id)], cb)
          .fail (msg) => @returnResult false, msg, cb
        else
          @createOrUpdate([@createInventoryEntry(msg.body.SKU, msg.body.QUANTITY, msg.body.EXPECTED_DELIVERY, msg.body.CHANNEL_ID)], cb)
      .fail (msg) => @returnResult false, msg, cb
      .done()
    else
      @returnResult false, 'No data found in elastic.io msg.', cb
