New J2K: Fix existing test data

j2k/testData/fileOrElement/mutableCollections/FunctionReturnValue.new.kt

@@ -0,0 +1,13 @@
+import java.util.ArrayList  
+
+internal class A {
+    fun createCollection(): MutableCollection<String?> {
+        return ArrayList()
+    }
+
+    fun foo(): Collection<String?> {
+        val collection = createCollection()
+        collection.add("a")
+        return collection
+    }
+}

j2k/testData/fileOrElement/mutableCollections/FunctionReturnValue2.new.kt

@@ -0,0 +1,21 @@
+import java.util.ArrayList
+
+internal class A {
+    private val collection: MutableCollection<String?>?
+
+    init {
+        collection = createCollection()
+    }
+
+    fun createCollection(): MutableCollection<String?> {
+        return ArrayList()
+    }
+
+    fun foo() {
+        collection!!.add("1")
+    }
+
+    fun getCollection(): Collection<String?>? {
+        return collection
+    }
+}

j2k/testData/fileOrElement/mutableCollections/Iterator2.new.kt

@@ -0,0 +1,11 @@
+class TestMutableCollection {
+    val list: MutableList<String?> = ArrayList()
+
+    fun test() {
+        val it = list.iterator()
+        while (it.hasNext()) {
+            val s = it.next()
+            if (s == "") it.remove()
+        }
+    }
+}