RemoveAt method
Implementation
void RemoveAt(int index) {
if (index < 0 || index >= this.Count) {
throw new RangeError.range(
index, 0, this.Count, "index", "Strings.IndexIsOutOfRange");
}
this[index].removeChangeEvent(this.SearchFilterChanged);
this._searchFilters.removeAt(index);
this.Changed();
}