diff --git a/tea/test.go b/tea/test.go
index bc18655..2c197a5 100644
--- a/tea/test.go
+++ b/tea/test.go
@@ -1,7 +1,20 @@
 package tea
 
-import "testing"
+import (
+	"fmt"
+	"testing"
+)
 
 type Test interface {
 	Run(*testing.T)
 }
+
+func fail(t string, args ...interface{}) Test {
+	return failure{cause: fmt.Errorf(t, args...)}
+}
+
+type failure struct {
+	cause error
+}
+
+func (f failure) Run(t *testing.T) { t.Error(f.cause.Error()) }
diff --git a/tea/tree.go b/tea/tree.go
index 87c162d..052e508 100644
--- a/tea/tree.go
+++ b/tea/tree.go
@@ -1,7 +1,7 @@
 package tea
 
 import (
-	// "reflect"
+	"reflect"
 	"testing"
 )
 
@@ -10,7 +10,7 @@ func Run(t *testing.T, tree *Tree) {
 	t.Run(tree.name, func(t *testing.T) {
 		setup(t, tree)
 
-		tree.test.Run(t)
+		clone(tree.test).Run(t)
 
 		for _, child := range tree.children {
 			if t.Failed() || t.Skipped() {
@@ -25,7 +25,7 @@ func Run(t *testing.T, tree *Tree) {
 func setup(t *testing.T, tree *Tree) {
 	if tree.parent != nil {
 		setup(t, tree.parent)
-		tree.parent.test.Run(t)
+		clone(tree.parent.test).Run(t)
 	}
 }
 
@@ -59,12 +59,12 @@ func (t *Tree) Child(test Test) *Tree {
 	return child
 }
 
-// func clone(t Test) Test {
-// 	T := reflect.TypeOf(t)
-// 	switch T.Kind() {
-// 	case reflect.Struct:
-// 	}
-// }
+func clone(t Test) Test {
+	srcV := reflect.ValueOf(t).Elem()
+	destV := reflect.New(srcV.Type())
+	destV.Elem().Set(srcV)
+	return destV.Interface().(Test)
+}
 
 func parseName(test Test) string {
 	if s, ok := test.(interface{ String() string }); ok {
diff --git a/tea_test.go b/tea_test.go
index 79c2ea0..8882288 100644
--- a/tea_test.go
+++ b/tea_test.go
@@ -16,7 +16,7 @@ type testThingSetup struct {
 func (test *testThingSetup) Run(t *testing.T) {
 	t.Logf("[%s] running testThingSetup", t.Name())
 	if test.thing != nil {
-		// t.Fatal("should be nil")
+		t.Fatal("should be nil")
 	}
 	test.thing = new(Thing)
 }
@@ -49,24 +49,18 @@ func (test *setKey) Run(t *testing.T) {
 func TestThing(t *testing.T) {
 	root := tea.New(new(testThingSetup))
 
-	{
-		root.Child(&setKey{key: "alice", value: "apple"})
-		root.Child(&setKey{key: "bob", value: "banana"})
-		root.Child(&setKey{key: "carol", value: "cherry"})
-	}
+	root.Child(&setKey{key: "alice", value: "apple"})
+	root.Child(&setKey{key: "bob", value: "banana"})
+	root.Child(&setKey{key: "carol", value: "cherry"})
 
-	{
-		bob := root.Child(&setKey{key: "b ob", value: "banana"})
-		bob.Child(&setKey{key: "car-el", value: "cherry"})
-		dave := bob.Child(&setKey{key: "dave", value: "durian"})
-		dave.Child(&setKey{key: "evan", value: "elderberry"})
-	}
+	bob := root.Child(&setKey{key: "b ob", value: "banana"})
+	bob.Child(&setKey{key: "car-el", value: "cherry"})
+	dave := bob.Child(&setKey{key: "dave", value: "durian"})
+	dave.Child(&setKey{key: "evan", value: "elderberry"})
 
-	{
-		root.Child(&setKey{key: "al ice", bad: true})
-		root.Child(&setKey{key: " alice", bad: true})
-		root.Child(&setKey{key: "alice ", bad: true})
-	}
+	root.Child(&setKey{key: "al ice", bad: true})
+	root.Child(&setKey{key: " alice", bad: true})
+	root.Child(&setKey{key: "alice ", bad: true})
 
 	tea.Run(t, root)
 }
diff --git a/thing.go b/thing.go
index d87fe4c..e3b63d4 100644
--- a/thing.go
+++ b/thing.go
@@ -12,6 +12,9 @@ var (
 )
 
 func validateKey(key string) error {
+	if strings.TrimSpace(key) == "" {
+		return fmt.Errorf("%w: key cannot be empty string", ErrInvalidKey)
+	}
 	if strings.Count(key, " ") > 0 {
 		return fmt.Errorf("%w: key cannot contain spaces", ErrInvalidKey)
 	}