removeAt method
删除指定索引的元素, 并发射
Implementation
T? removeAt(int index) {
if (_subject.isClosed) {
L.w('IO在close状态下请求发送数据');
return null;
}
final T element = latest!.elementAt(index);
if (element != null) {
_subject.add(latest?..removeAt(index));
}
return element;
}