oduct</span> <span class="o">=</span> <span class="n">_Item</span><span class="p">(</span><span class="n">item</span><span class="p">,</span> <span class="n">probability</span><span class="p">)</span>
                                <span class="n">tr</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">product</span><span class="p">)</span>
                            <span class="bp">self</span><span class="o">.</span><span class="n">_Database</span><span clas