code: def get_tensorboard_writer():
      """Return tensorboard writer. It can be None so no need
      to check if it is initialized."""
      return _GLOBAL_TENSORBOARD_WRITER
  
imports: import os
  import sys
  import torch
  from megatron import dist_signal_handler
  from megatron.tokenizer import build_tokenizer
  from .microbatches import build_num_microbatches_calculator
  from .timers import Timers
label_desc: Use image node_id 7 for calling a global function with example usage: get_tensorboard_writer() and returns: _GLOBAL_TENSORBOARD_WRITER