Update stats with info about resources consumed by a single client.

def RegisterResources(self, client_resources):
    """Update stats with info about resources consumed by a single client."""
    self.user_cpu_stats.RegisterValue(client_resources.cpu_usage.user_cpu_time)
    self.system_cpu_stats.RegisterValue(
        client_resources.cpu_usage.system_cpu_time)
    self.network_bytes_sent_stats.RegisterValue(
        client_resources.network_bytes_sent)

    self.worst_performers.Append(client_resources)
    new_worst_performers = sorted(
        self.worst_performers,
        key=lambda s: s.cpu_usage.user_cpu_time + s.cpu_usage.system_cpu_time,
        reverse=True)[:self.NUM_WORST_PERFORMERS]
    self.worst_performers = new_worst_performers