matplotlib: AttributeError: 'AxesSubplot' object has no attribute 'add_axes' : <p>Not sure exactly sure how to fix the following attribute error:</p>

<pre><code>AttributeError: 'AxesSubplot' object has no attribute 'add_axes'
</code></pre>

<p>The offending problem seems to be linked to the way I have set up my plot:</p>

<pre><code>gridspec_layout = gridspec.GridSpec(3,3)
pyplot_2 = fig.add_subplot(gridspec_layout[2])

ax = WCSAxes(fig, [0.1, 0.1, 0.8, 0.8], wcs=wcs)
pyplot_2.add_axes(ax)
</code></pre>

<p>Does anybody know how to solve this? Many thanks.</p>
