code: def _init_tag(self, tag):
          
          self._element = tag
  
          self._parseIsTag()
          self._parseIsComment()
  
          if not self._istag or self._iscomment:
              self._tagname = self._element
          else:
              self._parseTagName()
  
          if self._iscomment or not self._istag:
              return
  
          self._parseIsEndTag()
          self._parseIsNonPairTag()
  
          if self._istag and (not self._isendtag) or "=" in self._element:
              self._parseParams()
docs: True constructor, which really initializes the :class:`HTMLElement`.
  
          This is the function where all the preprocessing happens.
  
          Args:
              tag (str): HTML tag as string.