docs: public void replaceFromToWithFrom(int from, int to, AbstractDoubleList other, int otherFrom) {
  	// overridden for performance only.
  	if (! (other instanceof DoubleArrayList)) {
  		// slower
  		super.replaceFromToWithFrom(from,to,other,otherFrom);
  		return;
  	}
  	int length=to-from+1;
  	if (length>0) {
  		checkRangeFromTo(from, to, size());
  		checkRangeFromTo(otherFrom,otherFrom+length-1,other.size());
  		System.arraycopy(((DoubleArrayList) other).elements, otherFrom, elements, from, length);
  	}
  }