def _set_esp_key(self, v, load=False):
    """
    Setter method for esp_key, mapped from YANG variable /routing_system/interface/ve/ipv6/interface_ospfv3_conf/authentication/ipsec_auth_key_config/esp_key (ipsec-authentication-hexkey-string)
    If this variable is read-only (config: false) in the
    source YANG file, then _set_esp_key is considered as a private
    method. Backends looking to populate this variable should
    do so via calling thisObj._set_esp_key() directly.

    YANG Description: Hexadecimal key string for ESP
    """
    if hasattr(v, "_utype"):
      v = v._utype(v)
    try:
      t = YANGDynClass(v,base=RestrictedClassType(base_type=unicode, restriction_dict={'length': [u'0..80']}), is_leaf=True, yang_name="esp-key", rest_name="esp-key", parent=self, choice=(u'ch-algorithm', u'ca-esp-algorithm'), path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, extensions={u'tailf-common': {u'info': u'Hexadecimal key string for ESP', u'hidden': u'full', u'cli-incomplete-command': None}}, namespace='urn:brocade.com:mgmt:brocade-ospfv3', defining_module='brocade-ospfv3', yang_type='ipsec-authentication-hexkey-string', is_config=True)
    except (TypeError, ValueError):
      raise ValueError({
          'error-string': """esp_key must be of a type compatible with ipsec-authentication-hexkey-string""",
          'defined-type': "brocade-ospfv3:ipsec-authentication-hexkey-string",
          'generated-type': """YANGDynClass(base=RestrictedClassType(base_type=unicode, restriction_dict={'length': [u'0..80']}), is_leaf=True, yang_name="esp-key", rest_name="esp-key", parent=self, choice=(u'ch-algorithm', u'ca-esp-algorithm'), path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, extensions={u'tailf-common': {u'info': u'Hexadecimal key string for ESP', u'hidden': u'full', u'cli-incomplete-command': None}}, namespace='urn:brocade.com:mgmt:brocade-ospfv3', defining_module='brocade-ospfv3', yang_type='ipsec-authentication-hexkey-string', is_config=True)""",
        })

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