code: @SuppressWarnings("unchecked")
     public static <B> Class<? extends Builder<B>> builderForNonStrict(B built) {
        BuiltBy builtBy = built.getClass().getAnnotation(BuiltBy.class);
        if (builtBy == null) {
           return null;
        }
        return (Class<? extends Builder<B>>) builtBy.value();
     }
docs: The same as {@link org.infinispan.commons.configuration.ConfigurationUtils#builderFor(Object)} except that it won't
  throw an exception if no builder class is found.  Instead null will be returned.
  @param built The instance to find the builder for
  @param <B> The type of builder
  @return The builder for this instance or null if there isn't one