You're seeing just the callback handle_write_list, go back to Membrane.Sink module for more information.
Link to this callback

handle_write_list(pad, buffers, context, state)

View Source


Callback that is called when buffer should be written by the sink.

By default calls handle_write/4 for each buffer.

For pads in pull mode it is called when buffers have been demanded (by returning :demand action from any callback).

For pads in push mode it is invoked when buffers arrive.