Where to place the build script in the gem5 boot?

Question

I am following this tutorial https://gem5art.readthedocs.io/en/latest/tutorials/boot-tutorial.html

It is mentioned that it the following code has to be placed in the launch script. I could not find any such file.

gem5_repo = Artifact.registerArtifact(
    command = 'git clone https://gem5.googlesource.com/public/gem5',
    typ = 'git repo',
    name = 'gem5',
    path =  'gem5/',
    cwd = './',
    documentation = 'cloned gem5 from googlesource and checked out v20.1.0.0'
)

gem5_binary = Artifact.registerArtifact(
    command = '''cd gem5;
    git checkout v20.1.0.0;
    scons build/X86/gem5.opt -j8
    ''',
    typ = 'gem5 binary',
    name = 'gem5',
    cwd = 'gem5/',
    path =  'gem5/build/X86/gem5.opt',
    inputs = [gem5_repo,],
    documentation = 'gem5 binary based on v20.1.0.0'
)