public static void setSendSide(Object crumb) {
    if (ENABLED) {
      setBreadcrumb(Thread.currentThread(), CrumbType.SEND_SIDE, crumb);
    }
  }
set the "recipients" breadcrumb for a message while waiting for it
geode-core/src/main/java/org/apache/geode/internal/util/Breadcrumbs.java