ublic Optional<PsiClass> getExistInnerBuilderClass(@NotNull PsiClass psiClass,
                                                      @Nullable PsiMethod psiMethod,
                                                      @NotNull PsiAnnotation psiAnnotation) {
    final String builderClassName = getBuilderClassName(psiClass, psiAnnotation, psiMethod);
    return PsiClassUtil.getInnerClassInternByName(psiClass, builderClassName);
  }

ublic Optional<PsiClass> getExistInnerBuilderClass(@NotNull PsiClass psiClass,
                                                      @Nullable PsiMethod psiMethod,
                                                      @NotNull PsiAnnotation psiAnnotation) 