code: def htmlCtxtReadDoc(self, cur, URL, encoding, options):
          
          ret = libxml2mod.htmlCtxtReadDoc(self._o, cur, URL, encoding, options)
          if ret is None:raise treeError('htmlCtxtReadDoc() failed')
          __tmp = xmlDoc(_obj=ret)
          return __tmp
docs: parse an XML in-memory document and build a tree. This
             reuses the existing @ctxt parser context