replace method

T? replace(
  1. int index,
  2. T element
)

替换指定index的元素, 并发射

Implementation

T? replace(int index, T element) {
  if (_subject.isClosed) {
    L.w('IO在close状态下请求发送数据');
    return null;
  }

  _subject.add(latest?..[index] = element);
  return element;
}