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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_zone_id(self):
 """ Returns the Predix Zone Id for the service that is a required header in service calls. """

        if 'VCAP_SERVICES' in os.environ:
            services = json.loads(os.getenv('VCAP_SERVICES'))
            predix_asset = services['predix-asset'][0]['credentials']
            return predix_asset['zone']['http-header-value']
        else:
            return predix.config.get_env_value(self, 'zone_id')