private void initContactTransformers() {
    cache.put(new TransformKey(LinkedHashMap.class, VCard.class), new ToVCardTransformer());
    cache.put(
        new TransformKey(LinkedHashMap.class, Address.class), new ToVCardAddressTransformer());
    cache.put(new TransformKey(VCard.class, LinkedHashMap.class), new ToGraphContactTransformer());
    cache.put(
        new TransformKey(Address.class, LinkedHashMap.class), new ToGraphAddressTransformer());
  }
Dispatches to a cached function based on input and result types to perform a transformation.
extensions/data-transfer/portability-data-transfer-microsoft/src/main/java/org/datatransferproject/transfer/microsoft/transformer/TransformerServiceImpl.java