     if deliveriesDiffs
       # iterate over returnInfo instances
       _.each _.keys(deliveriesDiffs), (deliveryIndex) ->
-        if deliveryIndex != '_t'
+        if deliveryIndex isnt '_t'
           deliveryDiff = deliveriesDiffs[deliveryIndex]
           if _.isArray deliveryDiff
             # delivery was added

            returnInfo = returnInfoDiff
            # iterate over returnInfo items instances
            _.each _.keys(returnInfo.items), (returnInfoItemIndex) ->
              if returnInfoItemIndex != '_t'
                returnInfoItem = returnInfo.items[returnInfoItemIndex]
                # iterate over all returnInfo status actions
                _.each actionsListReturnInfoState(), (actionDefinition) ->

    if returnInfoDiffs
      # iterate over returnInfo instances
      _.each _.keys(returnInfoDiffs), (returnInfoIndex) ->
        if returnInfoIndex isnt '_t'
          returnInfoDiff = returnInfoDiffs[returnInfoIndex]
          if _.isArray returnInfoDiff
            # returnInfo was added
