code: def time_to_str(timestamp):
      """
      Convert seconds past Epoch to human readable string.
      """
      datetimestamp = datetime.datetime.fromtimestamp(timestamp)
      return "{:04d}-{:02d}-{:02d}-{:02d}-{:02d}-{:02d}".format(
          datetimestamp.year,
          datetimestamp.month,
          datetimestamp.day,
          datetimestamp.hour,
          datetimestamp.minute,
          datetimestamp.second,
      )
  
imports: from __future__ import with_statement
  from __future__ import division
  from __future__ import absolute_import
  import logging
  import os
  import shutil
  import time
  import re
  import datetime
  import traceback
  import torch
  import torch.optim.lr_scheduler
  from torch.nn.parallel import replicate, parallel_apply
  from torch.nn.parallel.scatter_gather import scatter_kwargs, gather
  from allennlp.common import Params
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.util import peak_memory_mb, gpu_memory_mb
  from allennlp.common.tqdm import Tqdm
  from allennlp.data.instance import Instance
  from allennlp.data.iterators.data_iterator import DataIterator
  from allennlp.models.model import Model
  from allennlp.nn import util
  from allennlp.training.learning_rate_schedulers import LearningRateScheduler
  from allennlp.training.optimizers import Optimizer
label_desc: Use image node_id 4 for calling a global function with example usage: time_to_str(timestamp) and returns: str