Add failing test based on issue cb372#90

caffeine/src/test/scala/foo/Issue90Spec.scala

@@ -0,0 +1,30 @@
+package foo
+
+import org.scalatest._
+
+/**
+ * Replicating the issue reported in https://github.com/cb372/scalacache/issues/90
+ */
+class Issue90Spec extends FlatSpec with Matchers {
+
+  "Issue 90" should "be fixed" in {
+    import scalacache._
+    import caffeine._
+    import scala.concurrent.duration._
+
+    implicit val scalaCache = ScalaCache(CaffeineCache())
+
+    def baz(): Seq[foo.Bar] = Seq(
+      Bar(1, "one"),
+      Bar(2, "two")
+    )
+    val ttl = 1.second
+
+    """
+    def logic(): Seq[foo.Bar] = sync.cachingWithTTL("the-key")(ttl)(baz())
+    """ should compile
+  }
+
+}
+
+case class Bar(a: Int, b: String)