code: def ctxtReadMemory(self, buffer, size, URL, encoding, options):
          
          ret = libxml2mod.xmlCtxtReadMemory(self._o, buffer, size, URL, encoding, options)
          if ret is None:raise treeError('xmlCtxtReadMemory() 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