private static @Nullable PsiType extractOptionalContent(@NotNull PsiClassType classType) {
    final PsiClass resolved = classType.resolve();
    if (resolved != null && CommonClassNames.JAVA_UTIL_OPTIONAL.equals(resolved.getQualifiedName())) {
      if (classType.getParameterCount() == 1) {
        return classType.getParameters()[0];
      }
    }
    return null;
  }
private static @Nullable PsiType extractOptionalContent(@NotNull PsiClassType classType)