code: public Observable<AgentPoolInner> getAsync(String resourceGroupName, String managedClusterName, String agentPoolName) {
          return getWithServiceResponseAsync(resourceGroupName, managedClusterName, agentPoolName).map(new Func1<ServiceResponse<AgentPoolInner>, AgentPoolInner>() {
              @Override
              public AgentPoolInner call(ServiceResponse<AgentPoolInner> response) {
                  return response.body();
              }
          });
      }
docs: Gets the agent pool.
  Gets the details of the agent pool by managed cluster and resource group.
  
  @param resourceGroupName The name of the resource group.
  @param managedClusterName The name of the managed cluster resource.
  @param agentPoolName The name of the agent pool.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the AgentPoolInner object