code: public Observable<PolicySetDefinitionInner> getBuiltInAsync(String policySetDefinitionName) {
          return getBuiltInWithServiceResponseAsync(policySetDefinitionName).map(new Func1<ServiceResponse<PolicySetDefinitionInner>, PolicySetDefinitionInner>() {
              @Override
              public PolicySetDefinitionInner call(ServiceResponse<PolicySetDefinitionInner> response) {
                  return response.body();
              }
          });
      }
docs: Retrieves a built in policy set definition.
  This operation retrieves the built-in policy set definition with the given name.
  
  @param policySetDefinitionName The name of the policy set definition to get.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PolicySetDefinitionInner object