public void removeAlertTarget(AlertTargetEntity alertTarget) {
    if (null != alertTargets) {
      alertTargets.remove(alertTarget);
    }

    alertTarget.removeAlertGroup(this);
  }
Removes the specified target from the targets that this group will dispatch
to.

@param alertTarget
         the target to remove (not {@code null}).
ambari-server/src/main/java/org/apache/ambari/server/orm/entities/AlertGroupEntity.java