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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 _get_client_address(self, req):
 """Get address from ``X-Forwarded-For`` header or use remote address. Remote address is used if the ``X-Forwarded-For`` header is not available. Note that this may not be safe to depend on both without proper authorization backend. Args: req (falcon.Request):
 falcon.Request object. Returns: str: client address. """

        try:
            forwarded_for = req.get_header('X-Forwarded-For', True)
            return forwarded_for.split(',')[0].strip()
        except (KeyError, HTTPMissingHeader):
            return (
                req.env.get('REMOTE_ADDR') if self.remote_address_fallback
                else None
            )