private String nextName(TypeElement element) {
      final String ifaceName = element.getQualifiedName().toString();
      String name;
      if (ifaceName.contains(".")) {
        name = ifaceName.substring(ifaceName.lastIndexOf('.') + 1);
      } else {
        name = ifaceName;
      }
      name = CaseFormat.UPPER_CAMEL.converterTo(CaseFormat.LOWER_CAMEL).convert(name);

      return name;
    }
Variable name based on facet element
value-processor/src/org/immutables/value/processor/meta/RepositoryModel.java