code: public Observable<VariableInner> getAsync(String resourceGroupName, String automationAccountName, String variableName) {
          return getWithServiceResponseAsync(resourceGroupName, automationAccountName, variableName).map(new Func1<ServiceResponse<VariableInner>, VariableInner>() {
              @Override
              public VariableInner call(ServiceResponse<VariableInner> response) {
                  return response.body();
              }
          });
      }
docs: Retrieve the variable identified by variable name.
  
  @param resourceGroupName Name of an Azure Resource group.
  @param automationAccountName The name of the automation account.
  @param variableName The name of variable.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the VariableInner object