public void append(byte[] utf8,int start,int len){
  setCapacity(length + len,true);
  System.arraycopy(utf8,start,bytes,length,len);
  length+=len;
}

public void append ( byte [ ] utf8 , int start , int len ) { setCapacity ( length + len , true ) ; System . arraycopy ( utf8 , start , bytes , length , len ) ; length += len ; }
append a range of bytes to the end of the given text
