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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 _is_range_request_processable(self, environ):
 """Return ``True`` if `Range` header is present and if underlying resource is considered unchanged when compared with `If-Range` header. """

        return (
            "HTTP_IF_RANGE" not in environ
            or not is_resource_modified(
                environ,
                self.headers.get("etag"),
                None,
                self.headers.get("last-modified"),
                ignore_if_range=False,
            )
        ) and "HTTP_RANGE" in environ