async fn modify_db_instance(
        &self,
        input: ModifyDBInstanceMessage,
    ) -> Result<ModifyDBInstanceResult, RusotoError<ModifyDBInstanceError>> {
        let mut request = SignedRequest::new("POST", "rds", &self.region, "/");
        let params = self.new_params("ModifyDBInstance");
        let mut params = params;
        ModifyDBInstanceMessageSerializer::serialize(&mut params, "", &input);
        request.set_payload(Some(serde_urlencoded::to_string(&params).unwrap()));
        request.set_content_type("application/x-www-form-urlencoded".to_owned());

        let response = self
            .sign_and_dispatch(request, ModifyDBInstanceError::from_response)
            .await?;

        let mut response = response;
        let result = xml_util::parse_response(&mut response, |actual_tag_name, stack| {
            xml_util::start_element(actual_tag_name, stack)?;
            let result =
                ModifyDBInstanceResultDeserializer::deserialize("ModifyDBInstanceResult", stack)?;
            skip_tree(stack);
            xml_util::end_element(actual_tag_name, stack)?;
            Ok(result)
        })
        .await?;

        drop(response); // parse non-payload
        Ok(result)
    }
<p>Modifies settings for a DB instance. You can change one or more database configuration parameters by specifying these parameters and the new values in the request. To learn what modifications you can make to your DB instance, call <a>DescribeValidDBInstanceModifications</a> before you call <a>ModifyDBInstance</a>.</p>
rusoto/services/neptune/src/generated.rs