docs: public boolean dropTrack( CombinedTrack<TD> track ) {
  		if( !tracksPureKlt.remove(track) )
  			if( !tracksReactivated.remove(track) )
  				if( !tracksDormant.remove(track) )
  					return false;
  
  		tracksUnused.add(track);
  		return true;
  	}