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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 add_to_stmts_rules(stmts, rules):
 """Use by plugins to add extra rules to the existing rules for a statement."""

    def is_rule_less_than(ra, rb):
        rka = ra[0]
        rkb = rb[0]
        if not util.is_prefixed(rkb):
            # old rule is non-prefixed; append new rule after
            return False
        if not util.is_prefixed(rka):
            # old rule prefixed, but new rule is not, insert
            return True
        # both are prefixed, compare modulename
        return rka[0] < rkb[0]
    for s in stmts:
        (arg, rules0) = stmt_map[s]
        for r in rules:
            i = 0
            while i < len(rules0):
                if is_rule_less_than(r, rules0[i]):
                    rules0.insert(i, r)
                    break
                i += 1
            if i == len(rules0):
                rules0.insert(i, r)