Reserved words

• _null_key_: Used for json path does not exist

          "$(body).superKey": {
            "Equals": "_null_key_"
          }

• _null_value_: Used for json path exists, but value is null

          "$(body).superKey": {
            "Equals": "_null_value_"
          }

• _ignore_assertion_: Used when want to ignore specific assertion for a case

          "$(body).superKey": {
            "Equals": "_ignore_assertion_"
          }

• __keys_count_: Used to count the keys (direct child keys) for a map or array

          "$(body).superKey._keys_count_": {
            "Equals": 5
          },
          "$(body)._keys_count_": {
            "Equals": 12
          }