Added a new test file that running the example given in Tree::Simple:…

…:Visitor object POD

t/test_visitor.t

@@ -0,0 +1,31 @@
+use v6;
+use Test;
+plan 1;
+BEGIN
+{
+    @*INC.push('lib');
+    @*INC.push('blib');
+}
+use Tree::Simple;
+use Tree::Simple::Visitor;
+
+# create a visitor instance
+my $visitor = Tree::Simple::Visitor.new();  							 
+
+# create a tree to visit
+my $tree = Tree::Simple.new($Tree::Simple::ROOT).addChildren(
+        Tree::Simple.new("1.0"),
+        Tree::Simple.new("2.0").addChild(
+                    Tree::Simple.new("2.1.0")),
+        Tree::Simple.new("3.0"));
+
+# by default this will collect all the 
+# node values in depth-first order into 
+# our results 
+$tree.accept($visitor);	  
+
+# get our results and print them
+my @results= <1.0 2.0 2.1.0 3.0>;
+
+is($visitor.getResults().join(', '), @results.join(', '),'Find correct children');  # prints "1.0, 2.0, 2.1.0, 3.0" 
+