public void deleteHost(final String hostName){
  if (hostName == null)   throw new IllegalArgumentException();
  knownHosts.remove(hostName);
}

public void deleteHost ( final String hostName ) { if ( hostName == null ) throw new IllegalArgumentException ( ) ; knownHosts . remove ( hostName ) ; }
drop counters for the named host . < p > note : there may be some interactions if another thread is currently in the middle of adding a counter for the host . what can happen is that the other thread gets the counters for the host and then returns the tmv for the metric while this method concurrently deletes the entry for the host from knownhosts . this would mean that the other thread has returned a tmv entry which is not going to remain visible . if there is a problem , it will be related to what is then done with that tmv entry .
