```// IntelliJ API Decompiler stub source generate...

# android-studio

[Rahul Singhal]

// IntelliJ API Decompiler stub source generated from a class file
// Implementation of methods is not available

package androidx.paging

@androidx.annotation.CheckResult public fun <T : R, R : kotlin.Any> androidx.paging.PagingData<T>.insertSeparators(generator: (T?, T?) -> R?): androidx.paging.PagingData<R> { /* compiled code */ }

how to see the source file for this.

java decompiler intellij plugin is already active in my AS. I see some of the class and almost all file which consist of extension functions are not showing the src code.
Also, I have tried clicking on Download sources but nothing happended.

I also found this: https://stackoverflow.com/questions/55096767/is-there-some-decompiler-for-kotlin-files-that-decompile-into-kotlin-kt-files