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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 protected_branches():
 # type: () -> list[str] """ Return branches protected by deletion. By default those are master and devel branches as configured in pelconf. Returns: list[str]: Names of important branches that should not be deleted. """

    master = conf.get('git.master_branch', 'master')
    develop = conf.get('git.devel_branch', 'develop')
    return conf.get('git.protected_branches', (master, develop))