async fn delete_db_subnet_group(
        &self,
        input: DeleteDBSubnetGroupMessage,
    ) -> Result<(), RusotoError<DeleteDBSubnetGroupError>> {
        let mut request = SignedRequest::new("POST", "rds", &self.region, "/");
        let params = self.new_params("DeleteDBSubnetGroup");
        let mut params = params;
        DeleteDBSubnetGroupMessageSerializer::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, DeleteDBSubnetGroupError::from_response)
            .await?;

        std::mem::drop(response);
        Ok(())
    }
<p><p>Deletes a DB subnet group.</p> <note> <p>The specified database subnet group must not be associated with any DB instances.</p> </note></p>
rusoto/services/neptune/src/generated.rs