Sending messages to a Parser process that is supervised by the first draft of MySupervisor

testing_my_supervisor_draft.iex

# Get a reference to one of the Parser process pid
iex(4)> parser_pid = MySupervisor.list_processes(pid) |> Map.keys |> List.first
#PID<0.124.0>

# Send a valid message
iex(5)> GenServer.call(parser_pid, "100")
100

# Send an invalid message
iex(6)> GenServer.call(parser_pid, "tyler")
** (exit) exited in: GenServer.call(#PID<0.112.0>, "tyler", 5000)
  # Stacktrace here

# Confirm the process died
iex(7)> Process.alive?(parser_pid)
false