From 6412798a47bd6d8074a63391caaee2462e377b2a Mon Sep 17 00:00:00 2001
From: Christophe Bedard <bedard.christophe@gmail.com>
Date: Tue, 31 Dec 2019 13:19:59 -0500
Subject: [PATCH] Define a (single) required event for Ros2Handler

---
 tracetools_analysis/tracetools_analysis/processor/ros2.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tracetools_analysis/tracetools_analysis/processor/ros2.py b/tracetools_analysis/tracetools_analysis/processor/ros2.py
index fb8dc9d..dedc08d 100644
--- a/tracetools_analysis/tracetools_analysis/processor/ros2.py
+++ b/tracetools_analysis/tracetools_analysis/processor/ros2.py
@@ -15,6 +15,7 @@
 """Module for trace events processor and ROS model creation."""
 
 from typing import Dict
+from typing import Set
 
 from tracetools_read import get_field
 
@@ -76,6 +77,12 @@ class Ros2Handler(EventHandler):
         # Temporary buffers
         self._callback_instances = {}
 
+    @staticmethod
+    def required_events() -> Set[str]:
+        return {
+            'ros2:rcl_init',
+        }
+
     @property
     def data(self) -> Ros2DataModel:
         return self._data_model