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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 subset(self, names):
 """Creates a new, flat EvalEnvironment that contains only the variables specified."""

        vld = VarLookupDict(self._namespaces)
        new_ns = dict((name, vld[name]) for name in names)
        return EvalEnvironment([new_ns], self.flags)