bufferCountWindow method
Buffers the stream and emits the buffer when EITHER:
a) the number of elements reaches count
, OR
b) the window
Stream emits
Implementation
Stream<List<T>> bufferCountWindow(int count, Stream window,
{ignoreEmptyWindows = true}) =>
transform(BufferCountWindowStreamTransformer(
count, (_) => window, 0, ignoreEmptyWindows));