MLLP.Dispatcher.dispatch

You're seeing just the callback dispatch, go back to MLLP.Dispatcher module for more information.
Link to this callback

dispatch( message_type, message, state )

Specs

dispatch(
  message_type :: atom(),
  message :: String.t(),
  state :: MLLP.FramingContext.t()
) :: {:ok, state :: MLLP.FramingContext.t()}