code: def _extract_header(content):
      content = content[2:].strip()
      index = content.find("=")
      key = content[:index].strip()
      value = content[index + 2 :].strip()
      return [key, value]
  
imports: from os.path import dirname, join, exists
  from torch.utils.data import Dataset
  from underthesea import pos_tag
  from underthesea import dependency_parse
  from underthesea.utils.col_analyzer import UDAnalyzer
label_desc: Use image node_id 4 for calling the UDSentence obj's underlying member method code with example usage: obj._extract_header(content) and returns: list