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: test_gem_resolver_installed_specification.rb
    path of file: ./repos/ruby/test/rubygems
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative "helper"

class TestGemResolverInstalledSpecification < Gem::TestCase
  def setup
    s
    
  def test_installable_platform_eh
    b, b_gem = util_gem "a", 1 do |s|
      s.platform = Gem::Platform.new %w[cpu other_platform 1]
    end

    source = Gem::Source::SpecificFile.new b_gem

    b_spec = Gem::Resolver::InstalledSpecification.new @set, b, source

    assert b_spec.installable_platform?
  end