Converter:

Preserve white spaces inside code blocks
Introduce WhiteSpaceSeparatedElementList which keeps track of whitespaces
Introduce StatementList
Change old test data accordingly

j2k/tests/testData/ast/annotations/jetbrainsNotNull.ide.kt

@@ -13,6 +13,7 @@ public class Test(str: String) {
         val test = "String2"
         sout(test)
         sout(dummy(test))
+
         Test(test)
     }
     {

j2k/tests/testData/ast/annotations/jetbrainsNotNull.kt

@@ -13,6 +13,7 @@ public open class Test(str: String) {
         var test: String = "String2"
         sout(test)
         sout(dummy(test))
+
         Test(test)
     }
     {