title: How to create a legend for 3D bar in matplotlib?
body: <p>Given <code>ax = plt.subplot()</code>:</p>
  
  <p><code>ax.bar()[0]</code> can be passed to <code>plt.legend()</code>.</p>
  
  <p>However, <code>ax.bar3d()</code> returns <code>None</code>. How do I create legend for displayed bars?</p>
  
  <p>UPDATE:</p>
  
  <p>Passing legend="stuff" to <code>ax.bar3d()</code> and than calling <code>ax.legend()</code> raises</p>
  
  <pre><code>/usr/lib/python2.6/site-packages/matplotlib/axes.py:4368: UserWarning: No labeled objects found. Use label='...' kwarg on individual plots.
  warnings.warn("No labeled objects found. "
  </code></pre>