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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 insert(self, i, arg):
 r"""Insert whitespace, an unparsed argument string, or an argument object. :param int i: Index to insert argument into :param Arg arg: Argument to insert 3 [RArg('arg0'), OArg('arg1'), OArg('arg2')] ['\n', RArg('arg0'), OArg('arg1'), OArg('arg2')] OArg('arg3') """

        arg = self.__coerce(arg)

        if isinstance(arg, Arg):
            super().insert(i, arg)

        if len(self) <= 1:
            self.all.append(arg)
        else:
            if i > len(self):
                i = len(self) - 1

            before = self[i - 1]
            index_before = self.all.index(before)
            self.all.insert(index_before + 1, arg)