more testing

Author: SethTisue

src/test/scala/scala/collection/immutable/TestLazyListExtensions.scala

@@ -107,4 +107,14 @@ class TestLazyListExtensions {
     val cyc = xs.cycle
     assertEquals(LazyList(1, 2, 3), cyc.take(3))
   }
+  @Test
+  def testSecondCallIsSafeButNotIdempotent(): Unit = {
+    val xs = LazyList(1, 2, 3)
+    // this is safe to do
+    val twice = xs.cycle.cycle
+    // and the contents are as expected
+    assertEquals(LazyList(1, 2, 3, 1, 2, 3, 1, 2), twice.take(8))
+    // but the result is not a cycle. TODO do we care?
+    assertFalse(twice.tail eq twice.tail.tail.tail.tail)
+  }
 }