@Override
  public boolean shutdownInProgress() {
    return membership.shutdownInProgress();
  }
Perform the grossness associated with sending a message over a DirectChannel

@param destinations the list of destinations
@param content the message
@return all recipients who did not receive the message (null if all received it)
@throws NotSerializableException if the message is not serializable
geode-core/src/main/java/org/apache/geode/distributed/internal/DistributionImpl.java