public InputStreamReader(InputStream in,CharsetDecoder dec){
  super(in);
  if (dec == null)   throw new NullPointerException("charset decoder");
  sd=StreamDecoder.forInputStreamReader(in,this,dec);
}

public InputStreamReader ( InputStream in , CharsetDecoder dec ) { super ( in ) ; if ( dec == null ) throw new NullPointerException ( "charset decoder" ) ; sd = StreamDecoder . forInputStreamReader ( in , this , dec ) ; }
creates an inputstreamreader that uses the given charset decoder .
