code: def _print_time_statistics(total_time):
      print(
          "N_EPOCH {}, MEAN {} s, STD {} s".format(
              len(total_time) - 1,
              np.mean(total_time[1:]),
              np.std(total_time[1:]),
          )
      )
  
file_path: dynet/examples/treelstm/scheduler.py
imports: import time
  import dynet
  import numpy
  from utils import acc_eval
label_desc: Use image node_id 3 for calling the Scheduler obj's underlying member method code with example usage: obj._print_time_statistics(total_time) without return types