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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 _reserved_symbols(self):
 """ Helper property for the build_remap_symbols method. This property first resolves _all_ local references from parents, skipping all locally declared symbols as the goal is to generate a local mapping for them, but in a way not to shadow over any already declared symbols from parents, and also the implicit globals in all children. This is marked "private" as there are a number of computations involved, and is really meant for the build_remap_symbols to use for its standard flow. """


        # In practice, and as a possible optimisation, the parent's
        # remapped symbols table can be merged into this instance, but
        # this bloats memory use and cause unspecified reservations that
        # may not be applicable this or any child scope.  So for clarity
        # and purity of references made, this somewhat more involved way
        # is done instead.
        remapped_parents_symbols = {
            self.resolve(v) for v in self.non_local_symbols}

        return (
            # block implicit children globals.
            self.global_symbols_in_children |
            # also not any global symbols
            self.global_symbols |
            # also all remapped parent symbols referenced here
            remapped_parents_symbols
        )