question: public In ( Socket socket ) { if ( socket == null ) throw new NullPointerException ( "argument is null" ) ; try { InputStream is = socket . getInputStream ( ) ; scanner = new Scanner ( new BufferedInputStream ( is ) , CHARSET_NAME ) ; scanner . useLocale ( LOCALE ) ; } catch ( IOException ioe ) { throw new IllegalArgumentException ( "Could not open " + socket ) ; } }
target:  Initializes an input stream from a socket.