@Override
    protected void process() {
      round = ImmutableRound.builder()
              .processing(processing())
              .round(round())
              .addCustomImmutableAnnotations(annotation.getCanonicalName())
              .build();

      try {
        statement.evaluate();
      } catch (Throwable e) {
        // means test failed
        thrown = e;
      }

      // mark that statement was executed
      wasEvaluated = true;
    }
Flag to track if test statement was executed or not. Fail fast if annotation processor
was not triggered. IE detected false (no-op) test executions
processor-testlib/src/org/immutables/value/processor/meta/ProcessorRule.java