Create from usage: Added tests.

idea/testData/quickfix/createFromUsage/iterator/afterCreateIteratorFromUsage1.kt

@@ -0,0 +1,9 @@
+// "Create method 'iterator' from usage" "true"
+class Foo<T> {
+    fun iterator(): Iterator<T> {
+        throw Exception("not implemented") //To change body of created methods use File | Settings | File Templates.
+    }
+}
+fun foo() {
+    for (i: Int in Foo<Int>()) { }
+}

idea/testData/quickfix/createFromUsage/iterator/afterCreateIteratorFromUsage2.kt

@@ -0,0 +1,12 @@
+// "Create method 'iterator' from usage" "true"
+class Foo<T> {
+    fun iterator(): Iterator<String> {
+        throw Exception("not implemented") //To change body of created methods use File | Settings | File Templates.
+    }
+}
+fun foo() {
+    for (i in Foo<Int>()) {
+        bar(i)
+    }
+}
+fun bar(i: String) { }

idea/testData/quickfix/createFromUsage/iterator/beforeCreateIteratorFromUsage1.kt

@@ -0,0 +1,5 @@
+// "Create method 'iterator' from usage" "true"
+class Foo<T>
+fun foo() {
+    for (i: Int in Foo<caret><Int>()) { }
+}

idea/testData/quickfix/createFromUsage/iterator/beforeCreateIteratorFromUsage2.kt

@@ -0,0 +1,8 @@
+// "Create method 'iterator' from usage" "true"
+class Foo<T>
+fun foo() {
+    for (i in Foo<caret><Int>()) {
+        bar(i)
+    }
+}
+fun bar(i: String) { }