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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 follow_file(self, f, seen, trim):
 """Whether to recurse into a file's dependencies."""

        return (f not in self.graph.nodes and
                f not in seen and
                (not trim or
                 not isinstance(self.provenance[f],
                                (resolve.Builtin, resolve.System))))