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: http_extra_headers_setting.rb
    path of file: ./repos/puppet/lib/puppet/settings
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class Puppet::Settings::HttpExtraHeadersSetting < Puppet::Settings::BaseSetting
  def type
    :http_extra_headers
  end

  def munge(headers)
    return headers if headers.is_a?(Hash)

    headers = headers.split(/\s*,\s*/) if headers.is_a?(String)

    raise ArgumentError, _("Expected an Array, String, or Hash, got a %{kl
    
  def munge(headers)
    return headers if headers.is_a?(Hash)

    headers = headers.split(/\s*,\s*/) if headers.is_a?(String)

    raise ArgumentError, _("Expected an Array, String, or Hash, got a %{klass}") % { klass: headers.class } unless headers.is_a?(Array)

    headers.map! { |header|
      case header
      when String
        header.split(':')
      when Array
        header
      else
        raise ArgumentError, _("Expected an Array or String, got a %{klass}") % { klass: header.class }
      end