restful sensor availability template is not evaluated about core HOT 6 OPEN

    def _update_from_rest_data(self) -> None:
        """Update state from the rest data."""
        try:
            value = self.rest.data_without_xml()
        except ExpatError as err:
            _LOGGER.warning(
                "REST xml result could not be parsed and converted to JSON: %s", err
            )
            value = self.rest.data

        if self._json_attrs:
            self._attr_extra_state_attributes = parse_json_attributes(
                value, self._json_attrs, self._json_attrs_path
            )

        raw_value = value

        if value is not None and self._value_template is not None:
            value = self._value_template.async_render_with_possible_json_value(
                value, None
            )

        if value is None or self.device_class not in (
            SensorDeviceClass.DATE,
            SensorDeviceClass.TIMESTAMP,
        ):
            self._attr_native_value = value
            self._process_manual_data(raw_value)
            self.async_write_ha_state()
            return

        self._attr_native_value = async_parse_date_datetime(
            value, self.entity_id, self.device_class
        )

        self._process_manual_data(raw_value)
        self.async_write_ha_state()

        if value is not None and self._value_template is not None:
            value = self._value_template.async_render_with_possible_json_value(
                value, None
            )

availability template (optional)
Defines a template if the entity state is available or not.

    def _update_from_rest_data(self) -> None:
        """Update state from the rest data."""
        try:
            value = self.rest.data_without_xml()
        except ExpatError as err:
            _LOGGER.warning(
                "REST xml result could not be parsed and converted to JSON: %s", err
            )
            value = self.rest.data

+        if self._availability is not None:
+            if not self._availability.async_render_with_possible_json_value(
+                value, None
+            ):
+                self._attr_native_value = STATE_UNAVAILABLE
+                self.async_write_ha_state()
+                return

        if self._json_attrs:
            self._attr_extra_state_attributes = parse_json_attributes(
                value, self._json_attrs, self._json_attrs_path
            )

        raw_value = value

        if value is not None and self._value_template is not None:
            value = self._value_template.async_render_with_possible_json_value(
                value, None
            )

        if value is None or self.device_class not in (
            SensorDeviceClass.DATE,
            SensorDeviceClass.TIMESTAMP,
        ):
            self._attr_native_value = value
            self._process_manual_data(raw_value)
            self.async_write_ha_state()
            return

        self._attr_native_value = async_parse_date_datetime(
            value, self.entity_id, self.device_class
        )

        self._process_manual_data(raw_value)
        self.async_write_ha_state()