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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 is_stored(self, i):
 """ Checks if the provided id is already in the vault. """

        if i in self.stored:
            return True

        try:
            with self._read_context(i):
                return True
        except (AngrVaultError, EOFError):
            return False