Creates a produce coroutine that collects the given flow.
This transformation is stateful, it launches a produce coroutine that collects the given flow and thus resulting channel should be properly closed or cancelled.
A channel with default buffer size is created.
Use buffer operator on the flow before calling
produceIn to specify a value other than
default and to control what happens when data is produced faster than it is consumed,
that is to control backpressure behavior.