code: public Observable<FunctionInner> getAsync(String resourceGroupName, String jobName, String functionName) {
          return getWithServiceResponseAsync(resourceGroupName, jobName, functionName).map(new Func1<ServiceResponseWithHeaders<FunctionInner, FunctionsGetHeaders>, FunctionInner>() {
              @Override
              public FunctionInner call(ServiceResponseWithHeaders<FunctionInner, FunctionsGetHeaders> response) {
                  return response.body();
              }
          });
      }
docs: Gets details about the specified function.
  
  @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 jobName The name of the streaming job.
  @param functionName The name of the function.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the FunctionInner object