def send_notification(self, subject="<STR_LIT>", message="<STR_LIT>", sender="<STR_LIT>", source=None, actions=None):
if self._pebble.firmware_version.major < <NUM_LIT:3>:<EOL><INDENT>self._send_legacy_notification(subject, message, sender, source)<EOL><DEDENT>else:<EOL><INDENT>self._send_modern_notification(subject, message, sender, source, actions)<EOL><DEDENT>
Sends a notification. Blocks as long as necessary.

:param subject: The subject.
:type subject: str
:param message: The message.
:type message: str
:param sender: The sender.
:type sender: str
:param source: The source of the notification
:type source: .LegacyNotification.Source
:param actions Actions to be sent with a notification (list of TimelineAction objects)
:type actions list