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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 match_star(self, tokens, item):
 """Matches starred assignment."""

        head_matches, last_matches = None, None
        if len(tokens) == 1:
            middle = tokens[0]
        elif len(tokens) == 2:
            if isinstance(tokens[0], str):
                middle, last_matches = tokens
            else:
                head_matches, middle = tokens
        else:
            head_matches, middle, last_matches = tokens
        self.add_check("_coconut.isinstance(" + item + ", _coconut.abc.Iterable)")
        if head_matches is None and last_matches is None:
            if middle != wildcard:
                self.add_def(middle + " = _coconut.list(" + item + ")")
        else:
            itervar = self.get_temp_var()
            self.add_def(itervar + " = _coconut.list(" + item + ")")
            with self.down_a_level():
                req_length = (len(head_matches) if head_matches is not None else 0) + (len(last_matches) if last_matches is not None else 0)
                self.add_check("_coconut.len(" + itervar + ") >= " + str(req_length))
                if middle != wildcard:
                    head_splice = str(len(head_matches)) if head_matches is not None else ""
                    last_splice = "-" + str(len(last_matches)) if last_matches is not None else ""
                    self.add_def(middle + " = " + itervar + "[" + head_splice + ":" + last_splice + "]")
                if head_matches is not None:
                    self.match_all_in(head_matches, itervar)
                if last_matches is not None:
                    for x in range(1, len(last_matches) + 1):
                        self.match(last_matches[-x], itervar + "[-" + str(x) + "]")