'RxDart convert Stream based on previous value

Lets say I have a Stream that emits a List followed by single elements like:

Stream.fromIterable([
  [1, 2, 3],
  4,
  5,
]);

How to convert it to a Stream that updates the previous element with current value and emits:

[1, 2, 3],
[1, 2, 3, 4],
[1, 2, 3, 4, 5],

flutter dart rxdart

Sources

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