code: def metric_to_str(self, metrics):
      format_str = ""
      for k in metrics:
          format_str += " {} = {:0.5f},".format(k.upper(), metrics[k])
  
      return format_str[:-1]
  
imports: import argparse
  import os
  import time
  import numpy
  import torch
  import torch.backends.cudnn
  import torch.multiprocessing
  from torch.utils.data import DataLoader
  from graph4nlp.pytorch.datasets.squad import SQuADDataset
  from graph4nlp.pytorch.modules.config import get_basic_args
  from graph4nlp.pytorch.modules.evaluation import BLEU, METEOR, ROUGE
  from graph4nlp.pytorch.modules.utils import constants
  from graph4nlp.pytorch.modules.utils.config_utils import get_yaml_config, update_values
  from graph4nlp.pytorch.modules.utils.copy_utils import prepare_ext_vocab
  from graph4nlp.pytorch.modules.utils.generic_utils import all_to_cuda
  from graph4nlp.pytorch.modules.utils.logger import Logger
  from .main import QGModel
label_desc: Use image node_id 7 for calling the ModelHandler obj's underlying member method code with example usage: obj.metric_to_str(metrics) and returns: format_str