def _set_af_ipv4_unicast(self, v, load=False):
    """
    Setter method for af_ipv4_unicast, mapped from YANG variable /routing_system/router/isis/router_isis_cmds_holder/address_family/ipv4/af_ipv4_unicast (container)
    If this variable is read-only (config: false) in the
    source YANG file, then _set_af_ipv4_unicast is considered as a private
    method. Backends looking to populate this variable should
    do so via calling thisObj._set_af_ipv4_unicast() directly.
    """
    if hasattr(v, "_utype"):
      v = v._utype(v)
    try:
      t = YANGDynClass(v,base=af_ipv4_unicast.af_ipv4_unicast, is_container='container', presence=True, yang_name="af-ipv4-unicast", rest_name="unicast", parent=self, path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, extensions={u'tailf-common': {u'info': u'IPv4 unicast address Family', u'cli-full-no': None, u'callpoint': u'IsisAfIpv4Ucast', u'cli-add-mode': None, u'cli-full-command': None, u'alt-name': u'unicast', u'cli-mode-name': u'config-router-isis-ipv4u'}}, namespace='urn:brocade.com:mgmt:brocade-isis', defining_module='brocade-isis', yang_type='container', is_config=True)
    except (TypeError, ValueError):
      raise ValueError({
          'error-string': """af_ipv4_unicast must be of a type compatible with container""",
          'defined-type': "container",
          'generated-type': """YANGDynClass(base=af_ipv4_unicast.af_ipv4_unicast, is_container='container', presence=True, yang_name="af-ipv4-unicast", rest_name="unicast", parent=self, path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, extensions={u'tailf-common': {u'info': u'IPv4 unicast address Family', u'cli-full-no': None, u'callpoint': u'IsisAfIpv4Ucast', u'cli-add-mode': None, u'cli-full-command': None, u'alt-name': u'unicast', u'cli-mode-name': u'config-router-isis-ipv4u'}}, namespace='urn:brocade.com:mgmt:brocade-isis', defining_module='brocade-isis', yang_type='container', is_config=True)""",
        })

    self.__af_ipv4_unicast = t
    if hasattr(self, '_set'):
      self._set()
Setter method for af_ipv4_unicast, mapped from YANG variable /routing_system/router/isis/router_isis_cmds_holder/address_family/ipv4/af_ipv4_unicast (container)
    If this variable is read-only (config: false) in the
    source YANG file, then _set_af_ipv4_unicast is considered as a private
    method. Backends looking to populate this variable should
    do so via calling thisObj._set_af_ipv4_unicast() directly.