You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: tainted_hash.rb
    path of file: ./repos/tainted_hash/lib
    
    the code of the file until where you have to start completion: class TaintedHash < Hash
  VERSION = "0.3.2"

  class UnexposedError 
    
  def untaint_original_hash(original_hash)
    hash = @new_class.new
    original_hash.each do |key, value|
      hash[key] = case value
        when TaintedHash then untaint_original_hash(value.instance_variable_get :@original_hash)
        else value
        end
    end