api: Implement GET /messages/<message_id>.

zulip/zulip/examples/get-raw-message

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import argparse
+
+import zulip
+
+usage = """get-raw-message <message_id> [options]
+
+
+Example: get-raw-message 42
+"""
+
+
+parser = zulip.add_default_arguments(argparse.ArgumentParser(usage=usage))
+parser.add_argument('message_id', type=int)
+options = parser.parse_args()
+
+client = zulip.init_from_options(options)
+
+print(client.get_raw_message(options.message_id))