Java: Don't extract method where it's not safe because of nullable result (IDEA-167391)

java/java-tests/testData/refactoring/extractMethod/ExitPoints11_after.java

@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.Nullable;
+
+class C {
+    private int[] list;
+
+    private int find(int id) {
+        Integer n = newMethod(id);
+        if (n != null) return n;
+        throw new RuntimeException();
+    }
+
+    @Nullable
+    private Integer newMethod(int id) {
+        for (int n : list) {
+            if (n == id) {
+                return n <= 0 ? 0 : n;
+            }
+        }
+        return null;
+    }
+}