code: public Observable<ServiceEndpointPolicyInner> beginUpdateAsync(String resourceGroupName, String serviceEndpointPolicyName) {
          return beginUpdateWithServiceResponseAsync(resourceGroupName, serviceEndpointPolicyName).map(new Func1<ServiceResponse<ServiceEndpointPolicyInner>, ServiceEndpointPolicyInner>() {
              @Override
              public ServiceEndpointPolicyInner call(ServiceResponse<ServiceEndpointPolicyInner> response) {
                  return response.body();
              }
          });
      }
docs: Updates service Endpoint Policies.
  
  @param resourceGroupName The name of the resource group.
  @param serviceEndpointPolicyName The name of the service endpoint policy.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the ServiceEndpointPolicyInner object