public void appendBytes(byte[] bs,int start,int len){
  elems=ArrayUtils.ensureCapacity(elems,length + len);
  System.arraycopy(bs,start,elems,length,len);
  length+=len;
}

public void appendBytes ( byte [ ] bs , int start , int len ) { elems = ArrayUtils . ensureCapacity ( elems , length + len ) ; System . arraycopy ( bs , start , elems , length , len ) ; length += len ; }
append ` len ' bytes from byte array , starting at given ` start ' offset .
