Removed methods not need anymore

j2k/src/org/jetbrains/kotlin/j2k/ForConverter.kt

@@ -123,7 +123,7 @@ class ForConverter(
 
     private fun convertToForeach(): ForeachStatement? {
         if (initialization is PsiDeclarationStatement) {
-            val loopVar = initialization.getDeclaredElements().singleOrNull2() as? PsiLocalVariable
+            val loopVar = initialization.getDeclaredElements().singleOrNull() as? PsiLocalVariable
             if (loopVar != null
                     && !loopVar.hasWriteAccesses(referenceSearcher, body)
                     && !loopVar.hasWriteAccesses(referenceSearcher, condition)

j2k/src/org/jetbrains/kotlin/j2k/SwitchConverter.kt

@@ -93,7 +93,7 @@ class SwitchConverter(private val codeConverter: CodeConverter) {
             false
         }
         else {
-            val block = case.statements.singleOrNull2() as? PsiBlockStatement
+            val block = case.statements.singleOrNull() as? PsiBlockStatement
             val statements = if (block != null) block.getCodeBlock().getStatements().toList() else case.statements
             !statements.any { it is PsiBreakStatement || it is PsiContinueStatement || it is PsiReturnStatement || it is PsiThrowStatement }
         }

j2k/src/org/jetbrains/kotlin/j2k/Utils.kt

@@ -120,9 +120,6 @@ fun PsiModifierListOwner.accessModifier(): String = when {
 
 fun PsiMethod.isMainMethod(): Boolean = PsiMethodUtil.isMainMethod(this)
 
-fun <T: Any> List<T>.singleOrNull2(): T? = if (size() == 1) this[0] else null
-fun <T: Any> Array<T>.singleOrNull2(): T? = if (size() == 1) this[0] else null
-
 fun PsiMember.isImported(file: PsiJavaFile): Boolean {
     if (this is PsiClass) {
         val fqName = getQualifiedName()