class Hash

def stringify_all_keys
  result = {}
  each do |k, v|
    result[k.to_s] = case v
                     when Hash, Array
                       v.stringify_all_keys
                     else
                       v
                     end
  end
  result
end

def symbolize_all_keys
  result = {}
  each do |k, v|
    result[k.to_sym] = case v
                       when Hash, Array
                         v.symbolize_all_keys
                       else
                         v
                       end
  end
  result
end