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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 initial_refcounts(self, initial_terms):
 """ Calculate initial refcounts for execution of this graph. Parameters initial_terms : iterable[Term] An iterable of terms that were pre-computed before graph execution. Each node starts with a refcount equal to its outdegree, and output nodes get one extra reference to ensure that they're still in the graph at the end of execution. """

        refcounts = self.graph.out_degree()
        for t in self.outputs.values():
            refcounts[t] += 1

        for t in initial_terms:
            self._decref_dependencies_recursive(t, refcounts, set())

        return refcounts