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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_repositories():
 """ Adds additional sources as defined in LINUX_PACKAGE_REPOSITORIES. """

    if not env.overwrite and env.LINUX_PACKAGE_REPOSITORIES == server_state('linux_package_repositories'): return
    if env.verbosity:
        print env.host, "UNCOMMENTING SOURCES in /etc/apt/sources.list and adding PPAs"
    if contains(filename='/etc/apt/sources.list',text='#(.?)deb(.*)http:(.*)universe'):

        _backup_file('/etc/apt/sources.list')
        uncomment('/etc/apt/sources.list','#(.?)deb(.*)http:(.*)universe',use_sudo=True)
    install_package('python-software-properties')
    for p in env.LINUX_PACKAGE_REPOSITORIES:
        sudo('add-apt-repository %s'% p)
        if env.verbosity:
            print 'added source', p
    set_server_state('linux_package_repositories',env.LINUX_PACKAGE_REPOSITORIES)