code: def log(self, extras=None):
      d = self.get(extras)
      strs = []
      for k, v in d.items():
          strs.append("{}: {:x<6f}".format(k, v))
      strs = ", ".join(strs)
      return strs
  
file_path: PaddleOCR/ppocr/utils/stats.py
imports: import collections
  import numpy
  import datetime
label_desc: Use image node_id 4 for calling the TrainingStats obj's underlying member method code with example usage: obj.log(extras) and returns: strs