Adapted tests to new API.

library/cwm/test/tree_pager_test.rb

@@ -17,10 +17,21 @@ def initialize(n)
     end
   end
 
+  class PagerTestTree < CWM::Tree
+    def label
+      "my tree pager"
+    end
+
+    def items
+      page = TestPage.new(42)
+      [
+        CWM::PagerTreeItem.new(page)
+      ]
+    end
+  end
+
   subject do
-    page = TestPage.new(42)
-    item = CWM::PagerTreeItem.new(page)
-    pager = CWM::TreePager.new(item, label: "my tree pager")
+    pager = CWM::TreePager.new(PagerTestTree.new)
     pager.init
     pager
   end

library/cwm/test/tree_test.rb

@@ -6,17 +6,23 @@
 require "cwm/tree"
 
 describe CWM::Tree do
-  subject do
-    CWM::Tree.new(
+  class TestTree < CWM::Tree
+    def label
+      "my tree"
+    end
+
+    def items
       [
-        CWM::TreeItem.new(:i1, "First", icon: "1st.png", open: false),
-        CWM::TreeItem.new(:i2, "Second", open: true, children: [
-                            CWM::TreeItem.new(:i21, "Nested")
-                          ])
-      ], label: "my tree"
-    )
+        new_item(:i1, "First", icon: "1st.png", open: false),
+        new_item(:i2, "Second", open: true, children: [
+                   new_item(:i21, "Nested")
+                 ])
+      ]
+    end
   end
 
+  subject { TestTree.new }
+
   include_examples "CWM::CustomWidget"
 
   describe "#items" do