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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 whoami(self) -> dict: """Returns the basic information about the authenticated character. Obviously doesn't do anything if this Preston instance is not authenticated, so it returns an empty dict. Args: None Returns: character info if authenticated, otherwise an empty dict """

        if not self.access_token:
            return {}
        self._try_refresh_access_token()
        return self.session.get(self.WHOAMI_URL).json()