class Hash

def deep_transform_keys(&block)

# => { "PERSON" => { "NAME" => "Rob", "AGE" => "28" } }
hash.deep_transform_keys{ |key| key.to_s.upcase }

hash = { person: { name: 'Rob', age: '28' } }

nested hashes and arrays.
This includes the keys from the root hash and from all
Return a new hash with all keys converted by the block operation. 
def deep_transform_keys(&block)
  _deep_transform_keys_in_object(self, &block)
end