code: public Observable<List<TypeFieldInner>> listFieldsByModuleAndTypeAsync(String resourceGroupName, String automationAccountName, String moduleName, String typeName) {
          return listFieldsByModuleAndTypeWithServiceResponseAsync(resourceGroupName, automationAccountName, moduleName, typeName).map(new Func1<ServiceResponse<List<TypeFieldInner>>, List<TypeFieldInner>>() {
              @Override
              public List<TypeFieldInner> call(ServiceResponse<List<TypeFieldInner>> response) {
                  return response.body();
              }
          });
      }
docs: Retrieve a list of fields of a given type identified by module name.
  
  @param resourceGroupName Name of an Azure Resource group.
  @param automationAccountName The name of the automation account.
  @param moduleName The name of module.
  @param typeName The name of type.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;TypeFieldInner&gt; object