question: @ Override public void write ( String str , int off , int len ) { int newcount = count + len ; if ( newcount > buf . length ) { buf = Arrays . copyOf ( buf , Math . max ( buf . length << 1 , newcount ) ) ; } str . getChars ( off , off + len , buf , count ) ; count = newcount ; }
target:  Write a portion of a string to the buffer.