code: def _nsattr(self, attr, ns=None):
          ''' returns an attribute name w/ namespace prefix'''
          if ns is None:
              return attr
          return '{' + self._ns[ns] + '}' + attf _nsattr(self, attr, ns=None):
          ''' returns an attribute name w/ namespace prefix'''
          if ns is None:
              return attr
          return '{' + self._ns[ns] + '}' + attr
docs: returns an attribute name w/ namespace prefix