Astarte.Device.send_datastream

You're seeing just the function send_datastream, go back to Astarte.Device module for more information.
Link to this function

send_datastream(pid, interface_name, path, value, opts \\ [])

Specs

send_datastream(
  pid :: pid(),
  interface_name :: String.t(),
  path :: String.t(),
  value :: term(),
  opts :: options
) :: :ok | {:error, reason :: term()}
when options: [option],
     option:
       {:qos, qos :: Tortoise.qos()} | {:timestamp, timestamp :: DateTime.t()}

Send a datastream value to Astarte.

This call is blocking and waits for the message to be ACKed at the MQTT level.