def sendPimV4JoinLeaveNgpf(self, routerId=None, pimObj=None, multicastIpAddress=None, action='join'):
        """
        Description
            Send PIMv4 joins or leaves.

            A PIM host object is acceptable.  If you don't know the PIM host object, use Device Group RouterID.
            Since a Device Group could have many routerID, you could state one of them.

            If multicastIpAddress is 'all', this will send join on all multicast addresses.
            Else, provide a list of multicast IP addresses to send join|leave.

        NOTE:
           Current support:  Each IP host multicast group address must be unique. IP hosts could send the same
                             multicast group address, but this API only supports unique multicast group address.
  
        Parameters
            routerId: The Device Group Router ID address.
            pimObj: '/api/v1/sessions/1/ixnetwork/topology/1/deviceGroup/1/ethernet/1/ipv4/1/pimV4Interface/1/pimV4JoinPruneList'
            multicastIpAddress: 'all' or a list of multicast IP addresses to send join.
                                 Example: ['225.0.0.3', '225.0.0.4']
            action: join|leave
        """
        # In case somebody passes in http://{ip:port}.  All this function needs is the Rest API.
        if pimObj:
            match = re.match('http://.*(/api.*)', pimObj)
            if match:
                pimObj = match.group(1)

        if routerId:
            deviceGroupObj = self.getDeviceGroupByRouterId(routerId=routerId)
            if deviceGroupObj == 0:
                raise IxNetRestApiException('No Device Group found for router ID: %s' % routerId)

            queryData = {'from': deviceGroupObj,
                        'nodes': [{'node': 'routerData', 'properties': [], 'where': []},
                                  {'node': 'ethernet', 'properties': [], 'where': []},
                                  {'node': 'ipv4', 'properties': [], 'where': []},
                                  {'node': 'pimV4Interface', 'properties': [], 'where': []}
                              ]}
            queryResponse = self.ixnObj.query(data=queryData)
            routerIdObj = queryResponse.json()['result'][0]['routerData'][0]['href']
            response = self.ixnObj.get(self.ixnObj.httpHeader+routerIdObj)
            routerIdMultivalue = response.json()['routerId']
            routerIdList = self.ixnObj.getMultivalueValues(routerIdMultivalue, silentMode=True)
            if routerId in routerIdList:
                pimObj = queryResponse.json()['result'][0]['ethernet'][0]['ipv4'][0]['pimV4Interface'][0]['href']

        # Based on the list of multicastIpAddress, get all their indexes.
        response = self.ixnObj.get(self.ixnObj.httpHeader+pimObj+'/pimV4JoinPruneList')

        startMcastAddrMultivalue = response.json()['groupV4Address']        
        listOfConfiguredMcastIpAddresses = self.ixnObj.getMultivalueValues(startMcastAddrMultivalue)

        self.ixnObj.logInfo('sendPimV4JoinNgpf: List of configured Mcast IP addresses: %s' % listOfConfiguredMcastIpAddresses)
        if listOfConfiguredMcastIpAddresses == []:
            raise IxNetRestApiException('sendPimV4JoinNgpf: No Mcast IP address configured')

        if multicastIpAddress == 'all':
            listOfMcastAddresses = listOfConfiguredMcastIpAddresses
        else:
            listOfMcastAddresses = multicastIpAddress

        # Note: Index position is not zero based.
        indexListToSend = []
        for eachMcastAddress in listOfMcastAddresses:
            index = listOfConfiguredMcastIpAddresses.index(eachMcastAddress)
            indexListToSend.append(index+1)

        url = pimObj+'/pimV4JoinPruneList/operations/%s' % action
        data = {'arg1': [pimObj+'/pimV4JoinPruneList'], 'arg2': indexListToSend}
        self.ixnObj.logInfo('sendPimv4JoinNgpf: %s' % url)
        self.ixnObj.logInfo('\t%s' % multicastIpAddress)
        response = self.ixnObj.post(self.ixnObj.httpHeader+url, data=data)
        self.ixnObj.waitForComplete(response, url+response.json()['id'])