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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 set_settings_secret(self, password):
 """Unlocks the secret data by passing the unlock password to the server. The server will cache the password for that machine. in password of type str The cipher key. raises :class:`VBoxErrorInvalidVmState` Virtual machine is not mutable. """

        if not isinstance(password, basestring):
            raise TypeError("password can only be an instance of type basestring")
        self._call("setSettingsSecret",
                     in_p=[password])