code: def parse_with(self, node):
          
  
          if 'instance' in node.lattrib:
              instance = node.lattrib['instance']
              list = None
              index = None
          elif 'list' in node.lattrib and 'index' in node.lattrib:
              instance = None
              list = node.lattrib['list']
              index = node.lattrib['index']
          else:
              self.raise_error('<With> must specify EITHER instance OR list & index')
  
          if 'as' in node.lattrib:
              as_ = node.lattrib['as']
          else:
              self.raise_error('<With> must specify a name for the '
                               'target instance')
  
          self.current_structure.add_with(With(instance, as_, list, index))
docs: Parses <With>
  
          @param node: Node containing the <With> element
          @type node: xml.etree.Element