code: public Observable<ManagedInstanceInner> getByResourceGroupAsync(String resourceGroupName, String managedInstanceName) {
          return getByResourceGroupWithServiceResponseAsync(resourceGroupName, managedInstanceName).map(new Func1<ServiceResponse<ManagedInstanceInner>, ManagedInstanceInner>() {
              @Override
              public ManagedInstanceInner call(ServiceResponse<ManagedInstanceInner> response) {
                  return response.body();
              }
          });
      }
docs: Gets a managed instance.
  
  @param resourceGroupName The name of the resource group that contains the resource. You can obtain this value from the Azure Resource Manager API or the portal.
  @param managedInstanceName The name of the managed instance.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the ManagedInstanceInner object