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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 _process_origin(self, req, resp, origin):
 """Inspects the request and adds the Access-Control-Allow-Origin header if the requested origin is allowed. Returns: ``True`` if the header was added and the requested origin is allowed, ``False`` if the origin is not allowed and the header has not been added. """

        if self._cors_config['allow_all_origins']:
            if self.supports_credentials:
                self._set_allow_origin(resp, origin)
            else:
                self._set_allow_origin(resp, '*')
            return True

        if origin in self._cors_config['allow_origins_list']:
            self._set_allow_origin(resp, origin)
            return True

        regex = self._cors_config['allow_origins_regex']
        if regex is not None:
            if regex.match(origin):
                self._set_allow_origin(resp, origin)
                return True

        return False