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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 _initialise(self, initial_state: str = 'unknown') -> dict: """Return a dictionary used to initialise a state object. This method is used to obtain a dictionary/hash describing the initial state of SDP or a service in SDP. Args: initial_state (str):
 Initial state. Returns: dict, Initial state configuration """

        initial_state = initial_state.lower()
        if initial_state != 'unknown' and \
                initial_state not in self._allowed_states:
            raise ValueError('Invalid initial state: {}'.format(initial_state))
        _initial_state = dict(
            current_state=initial_state,
            target_state=initial_state,
            current_timestamp=datetime.utcnow().isoformat(),
            target_timestamp=datetime.utcnow().isoformat())
        return _initial_state