module Guard::Commander

def pause(expected = nil)
  paused = listener.paused?
  states = { paused: true, unpaused: false, toggle: !paused }
  pause = states[expected || :toggle]
  fail ArgumentError, "invalid mode: #{expected.inspect}" if pause.nil?
  return if pause == paused
  listener.public_send(pause ? :pause : :start)
  UI.info "File event handling has been #{pause ? 'paused' : 'resumed'}"
end