def _unset_default_params(glyphs):
    """ Unset Glyphs.app's parameters that have default values.
    FIXME: (jany) maybe this should be taken care of in the writer? and/or
        classes should have better default values?
    """
    for glyphs_name, _, default_value in DEFAULT_PARAMETERS:
        if (
            glyphs_name in glyphs.customParameters
            and glyphs.customParameters[glyphs_name] == default_value
        ):
            del (glyphs.customParameters[glyphs_name])
        # These parameters can be referred to with the two names in Glyphs
        if (
            glyphs_name in glyphs.customParameters
            and glyphs.customParameters[glyphs_name] == default_value
        ):
            del (glyphs.customParameters[glyphs_name])