@Test
  public void testWarmup() throws Exception {
    InputAndExpected inputAndExpected =
        new InputAndExpected(pairList.get(0), VALID_MESSAGE_FORMAT_INPUT_STREAM_IMPLS[0], true);
    BlobIdTransformer transformer = new BlobIdTransformer(blobIdFactory, factory.getStoreKeyConverter());
    TransformationOutput output = transformer.transform(inputAndExpected.getInput());
    Assert.assertTrue("Should lead to IllegalStateException", output.getException() instanceof IllegalStateException);
    transformer.warmup(Collections.singletonList(inputAndExpected.getInput().getMessageInfo()), false);
    output = transformer.transform(inputAndExpected.getInput());
    assertNull(output.getException());
    verifyOutput(output.getMsg(), inputAndExpected.getExpected());
  }
Tests BlobIdTransformer's warmup() method
@throws Exception
ambry-replication/src/test/java/com/github/ambry/replication/BlobIdTransformerTest.java