@Override
  public String toString() {
    // instance specific for VM that executes this
    InternalDistributedSystem internalDS = InternalDistributedSystem.getAnyInstance();

    String stringInfo = "";

    if (internalDS != null && internalDS.isConnected()) {
      stringInfo = "Add/update the alert definitions" + " to " + internalDS.getDistributedMember()
          + " from " + getSender();
    } else { // when no DS instance found in current VM
      stringInfo = "InternalDistributedSystem instance not found, "
          + "no connection with DistributedSystem.";
    }
    return stringInfo;
  }
Returns String representation of this message object.
<p>
1. if the internalDS instance is not null & is connected, the returned string contains the
string as "... to [intended DistributedMember] from [sender DistributedMember]".
<p>
2. if the internalDS instance is null or is dis-connected, the returned string is -
"InternalDistributedSystem instance not found, no connection with DistributedSystem."

@return String representation of this message object.
geode-core/src/main/java/org/apache/geode/internal/admin/remote/UpdateAlertDefinitionMessage.java