test/trace_processor/parsing/cgroup_attach_task_pre_s.textproto

packet {
    ftrace_events {
      cpu: 3
      event {
        timestamp: 74289018336
        pid: 1
        cgroup_attach_task {
          dst_root: 1
          dst_id: 2
          pid: 3
          comm: "foo"
          cname: "bar"
        }
      }
    }
  }