docs: def header_check(self, content):
          """Special Python encoding check."""
  
          encode = None
  
          m = RE_PY_ENCODE.match(content)
          if m:
              if m.group(1):
                  encode = m.group(1).decode('ascii')
              elif m.group(2):
                  encode = m.group(2).decode('ascii')
          if encode is None:
              encode = 'utf-8'
          return encode