def state_attributes(self):
        """Return all attributes of the vehicle."""

        address_attributes = None
        if (self.current_address is not None):
            address_attributes = self.current_address.state_attributes()

        return {
            'id': self.identifier,
            'make': self.make,
            'model': self.model,
            'license_plate': self.license_plate,
            'active': self.active,
            'odo': self.odo,
            'latitude': self.latitude,
            'longitude': self.longitude,
            'altitude': self.altitude,
            'speed': self.speed,
            'last_seen': self.last_seen,
            'friendly_name': self.license_plate,
            'equipment_id': self.equipment_id,
            'fuel_level': self.fuel_level,
            'malfunction_light': self.malfunction_light,
            'coolant_temperature': self.coolant_temperature,
            'power_voltage': self.power_voltage,
            'current_max_speed': self.current_maximum_speed,
            'current_address': address_attributes
        }
Return all attributes of the vehicle.