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: gem_installer.rb
    path of file: ./repos/rubygems/bundler/lib/bundler/installer
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Bundler
  class GemInstaller
    attr_reader :spec, :standalone, :worker, :force, :installer

    def initialize(spec, installer, standalone = false, worker = 0, force = false)
      @spec = spec
      @installer = installer
      @standalone = standalone
      @worker = worker
      @force = force
    end

    def
    
    def install_from_spec
      post_install_message = install
      Bundler.ui.debug "#{worker}:  #{spec.name} (#{spec.version}) from #{spec.loaded_from}"
      generate_executable_stubs
      [true, post_install_message]
    rescue Bundler::InstallHookError, Bundler::SecurityError, Bundler::APIResponseMismatchError, Bundler::InsecureInstallPathError
      raise
    rescue Errno::ENOSPC
      [false, out_of_space_message]
    rescue Bundler::BundlerError, Gem::InstallError => e
      [false, specific_failure_message(e)]
    end