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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def visit_named_arg(self, _, children):
 """Named argument of a filter. Arguments --------- _ (node) : parsimonious.nodes.Node. children : list - 0: name of the arg - 1: for ``WS`` (whitespace):
 ``None``. - 2: operator - 3: for ``WS`` (whitespace):
 ``None``. - 4: value of the named arg Returns ------- .resources.NamedArg Instance of ``.resources.NamedArg``. Example ------- foo=1 bar="BAZ" quz=None foo=True bar=False """


        return self.NamedArg(
            arg=children[0],
            arg_type=children[2],
            value=children[4],
        )