ublic boolean validateExistingBuilderClass(@NotNull String builderClassName,
                                              @NotNull PsiClass psiClass,
                                              @NotNull ProblemSink problemSink) {
    final Optional<PsiClass> optionalPsiClass = PsiClassUtil.getInnerClassInternByName(psiClass, builderClassName);

    return optionalPsiClass.map(builderClass -> validateInvalidAnnotationsOnBuilderClass(builderClass, problemSink)).orElse(true);
  }

ublic boolean validateExistingBuilderClass(@NotNull String builderClassName,
                                              @NotNull PsiClass psiClass,
                                              @NotNull ProblemSink problemSink) 