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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_instance_guid(self, service_name):
 """ Returns the GUID for the service instance with the given name. """

        summary = self.space.get_space_summary()
        for service in summary['services']:
            if service['name'] == service_name:
                return service['guid']

        raise ValueError("No service with name '%s' found." % (service_name))