code: def parse_content(self, content):
          
          self.dom = self.xmlns = None
          self.data = {}
          # ignore empty xml file
          if len(content) > 3:
              self.raw = '\n'.join(content)
              self.dom = ET.fromstring(self.raw)
              self.xmlns = self.dom.tag.strip("{").split("}")[0] if all(c in self.dom.tag for c in ["{", "}"]) else ""
              self.data = self.parse_dom()
docs: All child classes inherit this function to parse XML file automatically.
          It will call the function :func:`parse_dom` by default to
          parser all necessary data to :attr:`data` and the :attr:`xmlns` (the
          default namespace) is ready for this function.