Performs SNMP GETNEXT query.

    Based on passed parameters, prepares SNMP GETNEXT packet
    (:RFC:`1905#section-4.2.2`) and schedules its transmission by
    :mod:`twisted` I/O framework at a later point of time.

    Parameters
    ----------
    snmpEngine : :class:`~pysnmp.hlapi.SnmpEngine`
        Class instance representing SNMP engine.

    authData : :class:`~pysnmp.hlapi.CommunityData` or :class:`~pysnmp.hlapi.UsmUserData`
        Class instance representing SNMP credentials.

    transportTarget : :class:`~pysnmp.hlapi.twisted.UdpTransportTarget` or :class:`~pysnmp.hlapi.twisted.Udp6TransportTarget`
        Class instance representing transport type along with SNMP peer address.

    contextData : :class:`~pysnmp.hlapi.ContextData`
        Class instance representing SNMP ContextEngineId and ContextName values.

    \*varBinds : :class:`~pysnmp.smi.rfc1902.ObjectType`
        One or more class instances representing MIB variables to place
        into SNMP request.

    Other Parameters
    ----------------
    \*\*options :
        Request options:

            * `lookupMib` - load MIB and resolve response MIB variables at
              the cost of slightly reduced performance. Default is `True`.
            * `ignoreNonIncreasingOid` - continue iteration even if response
              MIB variables (OIDs) are not greater then request MIB variables.
              Be aware that setting it to `True` may cause infinite loop between
              SNMP management and agent applications. Default is `False`.

    Returns
    -------
    deferred : :class:`~twisted.internet.defer.Deferred`
        Twisted Deferred object representing work-in-progress. User
        is expected to attach his own `success` and `error` callback
        functions to the Deferred object though
        :meth:`~twisted.internet.defer.Deferred.addCallbacks` method.

    Raises
    ------
    PySnmpError
        Or its derivative indicating that an error occurred while
        performing SNMP operation.

    Notes
    -----
    User `success` callback is called with the following tuple as
    its first argument:

    * errorStatus (str) : True value indicates SNMP PDU error.
    * errorIndex (int) : Non-zero value refers to `varBinds[errorIndex-1]`
    * varBinds (tuple) :
        A sequence of sequences (e.g. 2-D array) of
        :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances
        representing a table of MIB variables returned in SNMP response.
        Inner sequences represent table rows and ordered exactly the same
        as `varBinds` in request. Response to GETNEXT always contain
        a single row.

    User `error` callback is called with `errorIndication` object wrapped
    in :class:`~twisted.python.failure.Failure` object.

    Examples
    --------
    >>> from twisted.internet.task import react
    >>> from pysnmp.hlapi.twisted import *
    >>>
    >>> def success(args):
    ...     (errorStatus, errorIndex, varBindTable) = args
    ...     print(errorStatus, errorIndex, varBindTable)
    ...
    >>> def failure(errorIndication):
    ...     print(errorIndication)
    ...
    >>> def run(reactor):
    ...     d = nextCmd(SnmpEngine(),
    ...                 CommunityData('public'),
    ...                 UdpTransportTarget(('demo.snmplabs.com', 161)),
    ...                 ContextData(),
    ...                 ObjectType(ObjectIdentity('SNMPv2-MIB', 'system'))
    ...     d.addCallback(success).addErrback(failure)
    ...     return d
    ...
    >>> react(run)
    (0, 0, [[ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))]])

def nextCmd(snmpEngine, authData, transportTarget, contextData,
            *varBinds, **options):
    """Performs SNMP GETNEXT query.

    Based on passed parameters, prepares SNMP GETNEXT packet
    (:RFC:`1905#section-4.2.2`) and schedules its transmission by
    :mod:`twisted` I/O framework at a later point of time.

    Parameters
    ----------
    snmpEngine : :class:`~pysnmp.hlapi.SnmpEngine`
        Class instance representing SNMP engine.

    authData : :class:`~pysnmp.hlapi.CommunityData` or :class:`~pysnmp.hlapi.UsmUserData`
        Class instance representing SNMP credentials.

    transportTarget : :class:`~pysnmp.hlapi.twisted.UdpTransportTarget` or :class:`~pysnmp.hlapi.twisted.Udp6TransportTarget`
        Class instance representing transport type along with SNMP peer address.

    contextData : :class:`~pysnmp.hlapi.ContextData`
        Class instance representing SNMP ContextEngineId and ContextName values.

    \*varBinds : :class:`~pysnmp.smi.rfc1902.ObjectType`
        One or more class instances representing MIB variables to place
        into SNMP request.

    Other Parameters
    ----------------
    \*\*options :
        Request options:

            * `lookupMib` - load MIB and resolve response MIB variables at
              the cost of slightly reduced performance. Default is `True`.
            * `ignoreNonIncreasingOid` - continue iteration even if response
              MIB variables (OIDs) are not greater then request MIB variables.
              Be aware that setting it to `True` may cause infinite loop between
              SNMP management and agent applications. Default is `False`.

    Returns
    -------
    deferred : :class:`~twisted.internet.defer.Deferred`
        Twisted Deferred object representing work-in-progress. User
        is expected to attach his own `success` and `error` callback
        functions to the Deferred object though
        :meth:`~twisted.internet.defer.Deferred.addCallbacks` method.

    Raises
    ------
    PySnmpError
        Or its derivative indicating that an error occurred while
        performing SNMP operation.

    Notes
    -----
    User `success` callback is called with the following tuple as
    its first argument:

    * errorStatus (str) : True value indicates SNMP PDU error.
    * errorIndex (int) : Non-zero value refers to `varBinds[errorIndex-1]`
    * varBinds (tuple) :
        A sequence of sequences (e.g. 2-D array) of
        :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances
        representing a table of MIB variables returned in SNMP response.
        Inner sequences represent table rows and ordered exactly the same
        as `varBinds` in request. Response to GETNEXT always contain
        a single row.

    User `error` callback is called with `errorIndication` object wrapped
    in :class:`~twisted.python.failure.Failure` object.

    Examples
    --------
    >>> from twisted.internet.task import react
    >>> from pysnmp.hlapi.twisted import *
    >>>
    >>> def success(args):
    ...     (errorStatus, errorIndex, varBindTable) = args
    ...     print(errorStatus, errorIndex, varBindTable)
    ...
    >>> def failure(errorIndication):
    ...     print(errorIndication)
    ...
    >>> def run(reactor):
    ...     d = nextCmd(SnmpEngine(),
    ...                 CommunityData('public'),
    ...                 UdpTransportTarget(('demo.snmplabs.com', 161)),
    ...                 ContextData(),
    ...                 ObjectType(ObjectIdentity('SNMPv2-MIB', 'system'))
    ...     d.addCallback(success).addErrback(failure)
    ...     return d
    ...
    >>> react(run)
    (0, 0, [[ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))]])
    """
    def __cbFun(snmpEngine, sendRequestHandle,
                errorIndication, errorStatus, errorIndex,
                varBindTable, cbCtx):

        lookupMib, deferred = cbCtx

        if (options.get('ignoreNonIncreasingOid', False) and errorIndication
                and isinstance(errorIndication, errind.OidNotIncreasing)):
            errorIndication = None

        if errorIndication:
            deferred.errback(Failure(errorIndication))

        else:
            try:
                varBindTable = [
                    VB_PROCESSOR.unmakeVarBinds(snmpEngine.cache,
                                                varBindTableRow, lookupMib)
                    for varBindTableRow in varBindTable
                ]

            except Exception as e:
                deferred.errback(Failure(e))

            else:
                deferred.callback((errorStatus, errorIndex, varBindTable))

    addrName, paramsName = LCD.configure(
        snmpEngine, authData, transportTarget, contextData.contextName)

    varBinds = VB_PROCESSOR.makeVarBinds(snmpEngine.cache, varBinds)

    deferred = Deferred()

    cmdgen.NextCommandGenerator().sendVarBinds(
        snmpEngine, addrName, contextData.contextEngineId,
        contextData.contextName, varBinds, __cbFun,
        (options.get('lookupMib', True), deferred))

    return deferred