presto-proxy/src/main/java/io/prestosql/proxy/ProxyResource.java/ProxyResource/cancelQuery
class ProxyResource:    @DELETE
    @Path("/v1/proxy")
    @Produces(APPLICATION_JSON)
    public void cancelQuery(
            @QueryParam("uri") String uri,
            @QueryParam("hmac") String hash,
            @Context HttpServletRequest servletRequest,
            @Suspended AsyncResponse asyncResponse)
    {
        if (!hmac.hashString(uri, UTF_8).equals(HashCode.fromString(hash))) {
            throw badRequest(FORBIDDEN, "Failed to validate HMAC of URI");
        }

        Request.Builder request = prepareDelete().setUri(URI.create(uri));

        performRequest(servletRequest, asyncResponse, request, response -> responseWithHeaders(noContent(), response));
    }