Setter method for ext_vni_mask, mapped from YANG variable /overlay/access_list/type/vxlan/extended/ext_seq/ext_vni_mask (string)
    If this variable is read-only (config: false) in the
    source YANG file, then _set_ext_vni_mask is considered as a private
    method. Backends looking to populate this variable should
    do so via calling thisObj._set_ext_vni_mask() directly.

def _set_ext_vni_mask(self, v, load=False):
    """
    Setter method for ext_vni_mask, mapped from YANG variable /overlay/access_list/type/vxlan/extended/ext_seq/ext_vni_mask (string)
    If this variable is read-only (config: false) in the
    source YANG file, then _set_ext_vni_mask is considered as a private
    method. Backends looking to populate this variable should
    do so via calling thisObj._set_ext_vni_mask() directly.
    """
    if hasattr(v, "_utype"):
      v = v._utype(v)
    try:
      t = YANGDynClass(v,base=RestrictedClassType(base_type=unicode, restriction_dict={'pattern': u'0|[1-9a-fA-F][0-9a-fA-F]{0,5}'}), is_leaf=True, yang_name="ext-vni-mask", rest_name="vni-mask", parent=self, path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, extensions={u'tailf-common': {u'info': u'vni mask:Hexadecimal 0..FFFFFF', u'display-when': u'not(../ext-vni-any)', u'cli-incomplete-no': None, u'alt-name': u'vni-mask'}}, namespace='urn:brocade.com:mgmt:brocade-vxlan-visibility', defining_module='brocade-vxlan-visibility', yang_type='string', is_config=True)
    except (TypeError, ValueError):
      raise ValueError({
          'error-string': """ext_vni_mask must be of a type compatible with string""",
          'defined-type': "string",
          'generated-type': """YANGDynClass(base=RestrictedClassType(base_type=unicode, restriction_dict={'pattern': u'0|[1-9a-fA-F][0-9a-fA-F]{0,5}'}), is_leaf=True, yang_name="ext-vni-mask", rest_name="vni-mask", parent=self, path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, extensions={u'tailf-common': {u'info': u'vni mask:Hexadecimal 0..FFFFFF', u'display-when': u'not(../ext-vni-any)', u'cli-incomplete-no': None, u'alt-name': u'vni-mask'}}, namespace='urn:brocade.com:mgmt:brocade-vxlan-visibility', defining_module='brocade-vxlan-visibility', yang_type='string', is_config=True)""",
        })

    self.__ext_vni_mask = t
    if hasattr(self, '_set'):
      self._set()