collect_keyvalue_sample.rb

# Create a new hash and extend it with our CollectKeyValue
# module
hash ={
  "key_1"=>"one",
  "key_2"=>"two",
  "key_3"=>"three",
  "key_4"=>"four"
}.extend(CollectKeyValue)

# Now lets call our new hash#collect_kv method and rename
# "key" in the keys to "fish" (because we can!)
new_hash = hash.collect_kv do | key, value |
  new_key = key.gsub(/key/, "fish")
  [new_key, value]
end