def pref_to_str(pref_value):
    """If the value of a preference is None return an empty string type
    so we can write this data to a plist. Convert Bool values to strings
    for easy display in MunkiReport."""
    if pref_value is None:
        # convert to empty string for values that are not set
        pref_value = ''
    elif pref_value is True:
        pref_value = 'True'
    elif pref_value is False:
        pref_value = 'False'
    else:
        return pref_value
    return pref_value