Tests for KT-1888

 #KT-1888 fixed

idea/testData/codeInsight/overrideImplement/overrideExplicitFunction.kt

+trait A {
+    fun String.foo()
+}
+
+class B : A {
+    <caret>
+}
\ No newline at end of file

idea/testData/codeInsight/overrideImplement/overrideExplicitFunction.kt.after

+trait A {
+    fun String.foo()
+}
+
+class B : A {
+
+    override fun String.foo() {
+        throw UnsupportedOperationException()
+    }
+}
\ No newline at end of file

idea/testData/codeInsight/overrideImplement/overrideExplicitProperty.kt

+trait A {
+    val String.prop : Int
+}
+
+class B : A {
+    <caret>
+}
\ No newline at end of file

idea/testData/codeInsight/overrideImplement/overrideExplicitProperty.kt.after

+trait A {
+    val String.prop : Int
+}
+
+class B : A {
+
+    override val String.prop : Int = 0
+}
\ No newline at end of file

idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementTest.java

@@ -115,6 +115,14 @@ public class OverrideImplementTest extends LightCodeInsightFixtureTestCase {
         doMultiOverrideFileTest();
     }
 
+    public void testOverrideExplicitFunction() {
+        doOverrideFileTest();
+    }
+
+    public void testOverrideExplicitProperty() {
+        doOverrideFileTest();
+    }
+
     public void testComplexMultiOverride() {
         doMultiOverrideFileTest();
     }