code: func ManagedServiceInstanceGUID(managedServiceInstanceName string) string {
  	session := CF("curl", fmt.Sprintf("/v2/service_instances?q=name:%s", managedServiceInstanceName))
  	Eventually(session).Should(Exit(0))
  
  	rawJSON := strings.TrimSpace(string(session.Out.Contents()))
  
  	var serviceInstanceGUID ServiceInstanceGUID
  	err := json.Unmarshal([]byte(rawJSON), &serviceInstanceGUID)
  	Expect(err).NotTo(HaveOccurred())
  
  	Expect(serviceInstanceGUID.Resources).To(HaveLen(1))
  	return serviceInstanceGUID.Resources[0].Metadata.GUID
  }
docs: // ManagedServiceInstanceGUID returns the GUID for a managed service instance.