added a comment

ProcessTree.cpp

@@ -427,8 +427,21 @@ std::shared_ptr<ProcessTreeItem> ProcessTree::AddProcess(enum ProcessTreeSource
         ApplyFlags(process);
         _processes[pid] = process;
     }
-
-    // Call ReadProcEntry to ensure container ID is set if it's still empty
+
+    // The purpose of extracting the container ID from cgroup is to accurately identify
+    // the container in which a process is running. This is particularly important for
+    // monitoring and logging purposes in containerized environments, where applications
+    // are packaged and run in containers. By testing the extraction logic with various
+    // cgroup formats, we aim to ensure that the container ID is correctly identified in
+    // all scenarios.
+    // This method complements the existing logic that extracts the container ID from the
+    // command line arguments by providing an additional, more reliable source of information.
+    // This is especially relevant when the container ID is not found through the existing
+    // logic, which can happen when there is no parent process or when the parent process
+    // does not have the container ID set. This situation can occur in various scenarios,
+    // such as when a process is the root process of a container or when the process is
+    // started by a web service or another system service that does not pass the container
+    // ID through the command line arguments.
     if (process->_containerid.empty()) {
         auto p_temp = ReadProcEntry(pid);
         if (p_temp) {