def METHOD_NAME():
    w = WCS(HEADER_SOLAR)
    assert w.wcs.aux.rsun_ref is not None
    w.wcs.aux.rsun_ref = None
    assert w.wcs.aux.rsun_ref is None
    assert w.wcs.aux.dsun_obs is not None
    w.wcs.aux.dsun_obs = None
    assert w.wcs.aux.dsun_obs is None
    assert w.wcs.aux.crln_obs is not None
    w.wcs.aux.crln_obs = None
    assert w.wcs.aux.crln_obs is None
    assert w.wcs.aux.hgln_obs is not None
    w.wcs.aux.hgln_obs = None
    assert w.wcs.aux.hgln_obs is None
    assert w.wcs.aux.hglt_obs is not None
    w.wcs.aux.hglt_obs = None
    assert w.wcs.aux.hglt_obs is None
    assert str(w.wcs.aux) == "rsun_ref:\ndsun_obs:\ncrln_obs:\nhgln_obs:\nhglt_obs:"
    header = w.to_header()
    assert "RSUN_REF" not in header
    assert "DSUN_OBS" not in header
    assert "CRLN_OBS" not in header
    assert "HGLN_OBS" not in header
    assert "HGLT_OBS" not in header