to use to free the context (or NULL)</p>
                            </td>
                            <td class="parameter_annotations"> </td>
                        </tr>
                        <tr>
                            <td class="parameter_name"><p>map_context</p></td>
                            <td class="parameter_description"><p>the context to pass to the map function</p></td>
                            <td class="parameter_annotations"> </td>
                        </tr>
      