   @doc """
   Gets list of devices
   """
+  @spec get_devices(pid) :: list(%Bluex.Device{})
   def get_devices(pid) do
     GenServer.call(pid, :get_devices)
   end
 
   @doc false
+  @spec device_found(pid, %Bluex.Device{}) :: :ok
   def device_found(pid, device) do
     GenServer.cast(pid, {:device_found, device})
   end

  @doc """
  Gets list of adapters
  """
  def get_adapters(pid) do
    GenServer.call(pid, :get_adapters)
  end

  @doc """
  Starts Bluetooth discovery
  """
  @spec start_discovery(pid) :: :ok
  def start_discovery(pid) do
    GenServer.cast(pid, :start_discovery)
  end
