import com.google.protobuf.Message;
import com.satoshilabs.trezor.Trezor;
import com.satoshilabs.trezor.protobuf.TrezorMessage;

Trezor t = Trezor.getDevice(this);
if (t != null) {
  TrezorMessage.Initialize req = TrezorMessage.Initialize.newBuilder().build();
  Message resp = t.send(req);
  if (resp != null) {
    // "got: " + resp.getClass().getSimpleName()
  }
}