private ImmutableList<String> tryFindSubtypes(TypeElement supertypeElement) {
    ValueType surroundingType =
        MoreObjects.firstNonNull(containingType.enclosingValue, containingType);
    Set<ValueType> subtypes =
        surroundingType.getCases().knownSubtypesOf(supertypeElement.getQualifiedName().toString());
    ImmutableList.Builder<String> builder = ImmutableList.builder();
    for (ValueType valueType : subtypes) {
      builder.add(valueType.typeAbstract().toString());
    }
    return builder.build();
  }
Marshaled name for compatibility with repository.
@return get JSON name either specified or default.
value-processor/src/org/immutables/value/processor/meta/ValueAttribute.java