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: error.rb
    path of file: ./repos/excon/lib/excon
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
module Excon
  # Excon exception classes
  class Error < StandardError
    @default_status_error = :HTTPStatus

    class Stu
    
      def initialize(socket_error = Excon::Error.new)
        if is_a?(Certificate) || is_a?(Excon::Errors::CertificateError)
          super
        else
          super("#{socket_error.message} (#{socket_error.class})")
          set_backtrace(socket_error.backtrace)
          @socket_error = socket_error
        end