in_keys</span><span class="p">:</span> <span class="n">List</span><span class="p">[</span><span class="n">ProteinKey</span><span class="p">]</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">invariants</span><span class="o">.</span><span class="n">keys</span><span class="p">())</span>
        <span class="k">assert</span> <span class="nb">all</span><span class="p">(</span><span class="n">k</span> <span class="ow">in</span> <span class="n">invariants</span> <