code: def parse(content):
      
      values = {}
      for line in content.splitlines():
          lexer = shlex.shlex(line, posix=True)
          tokens = list(lexer)
  
          # parses the assignment statement
          if len(tokens) < 3:
              continue
  
          name, op = tokens[:2]
          value = ''.join(tokens[2:])
  
          if op != '=':
              continue
          if not re.match(r'[A-Za-z_][A-Za-z_0-9]*', name):
              continue
  
          value = value.replace(r'\n', '\n')
          value = value.replace(r'\t', '\t')
          values[name] = value
  
      return values
docs: Parse the content of a .env file (a line-delimited KEY=value format) into a
      dictionary mapping keys to values.