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: elixir_spec.rb
    path of file: ./repos/travis-build/spec/build/script
    
    the code of the file until where you have to start completion: require 'spec_helper'

describe Travis::Build::Script::Elixir, :sexp do
  let(:data)   { payload_for(:push, :elixir) }
  let(:script) { described_class.new(data) }
  subject      { script.sexp }
  it           { store_example }

  it_behaves_like 'a bash script'

  it_behaves_like 'compiled script' do
    let(:code) { ['TRAVIS_LANGUAGE=elixir'] }
  end

  it_behaves_like 'a build script sexp'

  it 'sets TRAVIS_OTP_RELEASE' do
    should include_sexp [:export, ['TRAVIS_OTP_RELEASE', '17.4']] #, echo: true
  end

  it 'sets TRAVIS_ELIXIR_VERSION' do
    should include_sexp [:export, ['TRAVIS_ELIXIR_VERSION', '1.0.2']] #, echo: true
  end

  it 'announces elixir version' do
    should include_sexp [:cmd, 'elixir --version', echo: true]
  end

  describe 'install' do
    it 'runs "mix local.hex"' do
      should include_sexp [:cmd, 'mix local.hex --force', assert: true, echo: true, timing: true]
    end
    it 'runs "mix deps.get"' do
      should include_sexp [:cmd, 'mix deps.get',  assert: true, echo: true, timing: true]
    end
  end

  describe 'script' do
    it 'runs "mix test"' do
      should include_sexp [:cmd, 'mix test', echo: true, timing: true]
    end
  end

  describe '#cache_slug' do
    subject { described_class.new(data).cache_slug }
    it { is_expected.to eq("cache-#{CACHE_SLUG_EXTRAS}--otp-17.4--elixir-1.0.2") }
  end

  def self.installs_required_otp_release(elixir_version, otp_release_wanted, otp_release_required)
    context "when elixir version is #{elixir_version}" do
      before :eac
    
  def self.installs_required_otp_release(elixir_version, otp_release_wanted, otp_release_required)
    context "when elixir version is #{elixir_version}" do
      before :each do
        data[:config][:elixir] = elixir_version
      end

      context "when OTP release is #{otp_release_wanted}" do
        before :each do
          data[:config][:otp_release] = otp_release_wanted
        end

        if otp_release_wanted == otp_release_required
          describe "wanted OTP release #{otp_release_wanted}" do
            it "is installed" do
              sexp = sexp_find(subject, [:if, "! -f ${TRAVIS_HOME}/otp/#{otp_release_wanted}/activate"], [:then])
              expect(sexp).to include_sexp([:raw, "archive_url=https://s3.amazonaws.com/travis-otp-releases/binaries/${travis_host_os}/${travis_rel_version}/$(uname -m)/erlang-#{otp_release_wanted}-nonroot.tar.bz2", assert: true])
              expect(sexp).to include_sexp([:cmd, "wget -o ${TRAVIS_HOME}/erlang.tar.bz2 ${archive_url}", assert: true, echo: true, timing: true])
            end
          end
        else
          describe "required OTP release #{otp_release_required}" do
            it "is installed" do
              sexp = sexp_find(subject, [:if, "! -f ${TRAVIS_HOME}/otp/#{otp_release_required}/activate"], [:then])
              expect(sexp).to include_sexp([:raw, "archive_url=https://s3.amazonaws.com/travis-otp-releases/binaries/${travis_host_os}/${travis_rel_version}/$(uname -m)/erlang-#{otp_release_required}-nonroot.tar.bz2", assert: true])
              expect(sexp).to include_sexp([:cmd, "wget -o ${TRAVIS_HOME}/erlang.tar.bz2 ${archive_url}", assert: true, echo: true, timing: true])
            end
          end
        end
      end
    end