documentation and another test

README.markdown

@@ -22,6 +22,19 @@ Call it straight from the module instead and this time cache it forever.
     SimpleRedisCache.cache('hello') { 'world' }
 ```
 
+Maybe we should cache something worth while.  If the result of the block is not a string, make sure to convert it to one.
+
+```ruby
+  require 'json'
+
+  JSON.parse(cache('20_perm_4', :ttl=>120){ (0..20).to_a.permutation(4).to_a.to_json })
+```
+
+Notice we serialize to json inside the block and from json outside the block.  Of course converting an enormous array
+to and from JSON is slower than the permutation so maybe it's not the best example.  Replace the above with an expensive
+databse calculation and it makes more sense.
+
+
 The above uses the default _Redis.new_ instance running on _127.0.0.1:6379_
 
 Let's configure a different redis instance.

test/simple_redis_cache_test.rb

@@ -48,5 +48,11 @@ def test_cache_on_module_method
     assert_equal(redis['hello'], 'world')
   end
 
+  require 'json'
+  def test_cache_permutations
+    assert_equal( (0..20).to_a.permutation(3).to_a, JSON.parse(cache('20_perm_4'){ (0..20).to_a.permutation(3).to_a.to_json }) )
+  end
+
+
 
 end