presto-proxy/src/main/java/io/prestosql/proxy/ProxyResource.java/ProxyResource/badRequest
class ProxyResource:    private static WebApplicationException badRequest(Status status, String message)
    {
        throw new WebApplicationException(
                Response.status(status)
                        .type(TEXT_PLAIN_TYPE)
                        .entity(message)
                        .build());
    }