if ( fd <= 0 ) return;
if ( fd <= 0 ) { System.out.println( "RXTXPort:close detected bad File Descriptor" ); return; }
	public synchronized void close()	{		if (debug)			System.out.println("RXTXPort:close(" + this.name + " )"); 		if ( fd <= 0 ) return;		setDTR(false);		setDSR(false);		nativeClose( this.name );		super.close();		removeEventListener();		fd = 0;		Runtime.getRuntime().gc();	}