def addusersitepackages(known_paths):
    global USER_BASE, USER_SITE, ENABLE_USER_SITE
    env_base = os.environ.get("PYTHONUSERBASE", None)

    def joinuser(*args):
        return os.path.expanduser(os.path.join(*args))

    #if sys.platform in ('os2emx', 'riscos'):
    #    # Don't know what to put here
    #    USER_BASE = ''
    #    USER_SITE = ''
    if os.name == "nt":
        base = os.environ.get("APPDATA") or "~"
        USER_BASE = env_base if env_base else joinuser(base, "Python")
        USER_SITE = os.path.join(USER_BASE,
                                 "Python" + sys.version[0] + sys.version[2],
                                 "site-packages")
    else:
        USER_BASE = env_base if env_base else joinuser("~", ".local")
        USER_SITE = os.path.join(USER_BASE, "lib",
                                 "python" + sys.version[:3],
                                 "site-packages")

    if ENABLE_USER_SITE and os.path.isdir(USER_SITE):
        addsitedir(USER_SITE, known_paths)
    return known_paths
``ApplicationNodeDeployer.calculate_changes`` returns a
dataset/ETHPy150Open deanhiller/databus/webapp/play1.3.x/python/Lib/site.py/addusersitepackages--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/test/test_container.py/ApplicationNodeDeployerCalculateChangesTests.test_no_state_changes