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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 _build_url(self, endpoint):
 """ Builds the absolute URL using the target and desired endpoint. """

        try:
            path = self.endpoints[endpoint]
        except KeyError:
            msg = 'Unknown endpoint `{0}`'
            raise ValueError(msg.format(endpoint))
        absolute_url = urljoin(self.target, path)
        return absolute_url