@SuppressWarnings("SameParameterValue")
  private <T> void deployFunction(Class<? extends Function<T>> functionClass) {
    Path functionJarPath = rootFolder.resolve(functionClass.getSimpleName() + ".jar");

    Throwable thrown =
        catchThrowable(() -> writeJarFromClasses(functionJarPath.toFile(), functionClass));

    assertThat(thrown)
        .as("Exception from writing function JAR")
        .isNull();

    String deployFunctionCommand = "deploy --jar=" + functionJarPath;
    gfshRule.execute(connectCommand, deployFunctionCommand);
  }
Acceptance tests for function executions timer on a loner server with no locator
geode-assembly/src/acceptanceTest/java/org/apache/geode/metrics/function/executions/FunctionExecutionsTimerLonerTest.java