def find_argname(self, argname, rec=False):
if self.args:  <EOL><INDENT>return _find_arg(argname, self.args, rec)<EOL><DEDENT>return None, None<EOL>
Get the index and :class:`AssignName` node for given name.

        :param argname: The name of the argument to search for.
        :type argname: str

        :param rec: Whether or not to include arguments in unpacked tuples
            in the search.
        :type rec: bool

        :returns: The index and node for the argument.
        :rtype: tuple(str or None, AssignName or None)