def modifyTrafficItemIpPriorityTos(self, trafficItemObj=None, trafficItemName=None, endpointSetName=None,
                                       packetHeaderName='ipv4', fieldName='Precedence', values=None):
        """
        Description
           Modify a Traffic Item Flow group IP Priority TOS fields.

        Parameters
           value: <dict>: {'fieldValue': '000 Routine'|'001 Priority'|'010 Immediate'|'011 Flash'|'100 Flash Override'
                           '101 CRITIC/ECP'|'110 Internetwork Control'}
        
           trafficItemObj: <str|obj>: The Traffic Item object handle.
           trafficItemName: <str|obj>: The Traffic Item name.
           endpointSetName: <str|obj>: The endpointSet name (Flow-Group).

           Option #1: trafficItemName + endpointSetName
           Option #2: trafficItemObj + endpointSetName
           Option #3: trafficItemName only (Will assume there is only one configElement object)
           Option #4: trafficItemObj only  (Will assume there is only one configElement object)

        Requirement
           Call self.getConfigElementObj() to get the config element object first.

        Example
           trafficObj.modifyTrafficItemIpPriorityTos(trafficItemName='Raw MPLS/UDP', values={'fieldValue': '001 Priority'})
        """
        configElementObj = self.getConfigElementObj(trafficItemObj=trafficItemObj, trafficItemName=trafficItemName,
                                                    endpointSetName=endpointSetName)

        self.modifyTrafficItemPacketHeader(configElementObj, packetHeaderName=packetHeaderName,
                                           fieldName=fieldName, values=values)