[Project Structure Interface] Unexpected behavior for KtClassBody.add() method Follow

Hello everyone!

I'm trying to add a KtProperty into KtClassBody

I obtain a KtClassBody like this:

val ktClass = ktPsiFactory.createClass("class Test {}")
val ktClassBody = ktClass.getChildOfType<KtClassBody>()

Then, I create a KtProperty and try to add it into KtClassBody:

val ktProperty = ktPsiFactory.createProperty("private val intValue: Int = 0")
ktClassBody?.add(ktProperty)

Finally, I add the KtFile that containing the ktClass in PsiDirectory and check the generation result.

But I find the generation result is incorrectly:

class Test {}
 private val intValue: Int = 0

What's wrong with my code and how can I solve it? Thank you! Have a happy day :)