human
Here's a good function header given the following:
I wrote the below code

    import matplotlib.pyplot as plt
    evoked = _get_epochs().average()
    plot_evoked_topo([evoked, evoked], merge_grads=True, background_color='w')
    evoked.plot_joint()
    def return_inds(d):
        return list(range(d.shape[0]))
    evoked.plot_joint(title='test', topomap_args=dict(contours=0, res=8), ts_args=dict(spatial_colors=True, zorder=return_inds))
    assert_raises(ValueError, evoked.plot_joint, ts_args=dict(axes=True))
    warnings.simplefilter('always', UserWarning)
    picked_evoked = evoked.copy().pick_channels(evoked.ch_names[:3])
    picked_evoked_eeg = evoked.copy().pick_types(meg=False, eeg=True)
    picked_evoked_eeg.pick_channels(picked_evoked_eeg.ch_names[:3])
    with warnings.catch_warnings(record=True):
        for ylim in [dict(mag=[(-600), 600]), None]:
            plot_evoked_topo(([picked_evoked] * 2), layout, ylim=ylim)
        for evo in [evoked, [evoked, picked_evoked]]:
            assert_raises(ValueError, plot_evoked_topo, evo, layout, color=['y', 'b'])
        evoked_delayed_ssp = _get_epochs_delayed_ssp().average()
        ch_names = evoked_delayed_ssp.ch_names[:3]
        picked_evoked_delayed_ssp = pick_channels_evoked(evoked_delayed_ssp, ch_names)
        fig = plot_evoked_topo(picked_evoked_delayed_ssp, layout, proj='interactive')
        func = _get_presser(fig)
        event = namedtuple('Event', ['inaxes', 'xdata', 'ydata'])
        func(event(inaxes=fig.axes[0], xdata=fig.axes[0]._mne_axs[0].pos[0], ydata=fig.axes[0]._mne_axs[0].pos[1]))
        func(event(inaxes=fig.axes[0], xdata=0, ydata=0))
        params = dict(evokeds=[picked_evoked_delayed_ssp], times=picked_evoked_delayed_ssp.times, fig=fig, projs=picked_evoked_delayed_ssp.info['projs'])
        bools = ([True] * len(params['projs']))
        _plot_update_evoked_topo_proj(params, bools)
    plot_evoked_topo(picked_evoked_eeg.copy(), fig_background=np.zeros((4, 3, 3)), proj=True, background_color='k')
    picked_evoked.plot_topo(merge_grads=True, background_color='w')
    plt.close('all')
    for (ax,...

What's a good function header?
assistant
#Here's a good function header.

def test_plot_topo():