<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def visit_root(self, _, children):
 """The main node holding all the query. Arguments --------- _ (node) : parsimonious.nodes.Node. children : list - 0: for ``WS`` (whitespace):
 ``None``. - 1: for ``NAMED_RESOURCE``: an instance of a subclass of ``.resources.Resource``. - 2: for ``WS`` (whitespace):
 ``None``. Returns ------- .resources.Resource An instance of a subclass of ``.resources.Resource``, with ``is_root`` set to ``True``. Example ------- <Field[foo] /> True <List[bar]> <Field[name] /> </List[bar]> True <Object[baz]> <Field[name] /> </Object[baz]> True """


        resource = children[1]
        resource.is_root = True
        return resource