public static Read<String> readStrings() {
    return Read.newBuilder(
            (PubsubMessage message) -> new String(message.getPayload(), StandardCharsets.UTF_8))
        .setCoder(StringUtf8Coder.of())
        .build();
  }
@Test
  public void testRuntimeValueProviderSubscription() {
    TestPipeline pipeline = TestPipeline.create();
    ValueProvider<String> subscription =
        pipeline.newProvider("projects/project/subscriptions/subscription");
    Read<String> pubsubRead = PubsubIO.readStrings().fromSubscription(subscription);
    pipeline.apply(pubsubRead);
    assertThat(pubsubRead.getSubscriptionProvider(), not(nullValue()));
    assertThat(pubsubRead.getSubscriptionProvider().isAccessible(), is(false));
  }