temporary

# File lib/bundler/settings.rb, line 136
    def temporary(update)
      existing = Hash[update.map {|k, _| [k, @temporary[key_for(k)]] }]
      update.each do |k, v|
        set_key(k, v, @temporary, nil)
      end
      return unless block_given?
      begin
        yield
      ensure
        existing.each {|k, v| set_key(k, v, @temporary, nil) }
      end
    end