multiple matplotlib gridspec's in single figure BUT each one with their own common title
<p>I know I can use <code>update</code> to adjust the parameters of a <code>GridSpec</code> instance in a matplotlib figure, allowing to arrange multiple gridspec's in a single figure. Much as in this example taken from the matplotlib doc</p>

<pre><code>gs1 = gridspec.GridSpec(3, 3)
gs1.update(left=0.05, right=0.48, wspace=0.05)
ax1 = plt.subplot(gs1[:-1, :])
ax2 = plt.subplot(gs1[-1, :-1])
ax3 = plt.subplot(gs1[-1, -1])

gs2 = gridspec.GridSpec(3, 3)
gs2.update(left=0.55, right=0.98, hspace=0.05)
ax4 = plt.subplot(gs2[:, :-1])
ax5 = plt.subplot(gs2[:-1, -1])
ax6 = plt.subplot(gs2[-1, -1])
</code></pre>

<p>But how can I give both <code>gs1</code> and <code>gs2</code> their own common title? Using <code>suptitle</code> I only get a common title for the whole figure at once.</p>