bufferCount method Null safety
Buffers a number of values from the source Stream by
emits the buffer and clears it, and starts a new buffer each
startBufferEvery values. If
startBufferEvery is not provided,
then new buffers are started immediately at the start of the source
and when each buffer closes and is emitted.
count is the maximum size of the buffer emitted
RangeStream(1, 4) .bufferCount(2) .listen(print); // prints [1, 2], [3, 4] done!
startBufferEvery is 2, then a new buffer will be started
on every other value from the source. A new buffer is started at the
beginning of the source by default.
RangeStream(1, 5) .bufferCount(3, 2) .listen(print); // prints [1, 2, 3], [3, 4, 5],  done!
Stream<List<T>> bufferCount(int count, [int startBufferEvery = 0]) => transform(BufferCountStreamTransformer<T>(count, startBufferEvery));