title: Close an ExpansionTile when another ExpansionTile is tapped
body: <p>I have a list of ExpansionTile with a list of ListTile in a Drawer. What I want to achieve is, when I press an ExpansionTile, the another ExpansionTile must be collapsed. I had been stuck with this problem for two days and could not find an answer. Can anybody know how to collapse the ExpansionTile programmatically?</p>
  <p><strong>Note:</strong></p>
  <p>I don't want to mess up the animation of the widget.</p>
  <p>Here is my code,</p>
  <pre><code>ListView.builder(
                  itemCount: userList.length,
                  shrinkWrap: true,
                  itemBuilder: (BuildContext context, findex) {
                    return ExpansionTile(
                      key: Key(findex.toString()),
                      title: Text(userList[findex].parentdata[0].title,
                        style: TextStyle(fontSize: 15.0, fontWeight: FontWeight.bold,color: Colors.black),
                      ),
                      onExpansionChanged: (value) {
                      },
                      children: [
                        ListView.builder(
                          itemCount: userList[findex].document.length,
                          shrinkWrap: true,
                          itemBuilder: (BuildContext context, sindex) {
                            return ListTile(
                              title: Text(
                                  userList[findex].document[sindex].title,
                                style: TextStyle(fontSize: 15.0, fontWeight: FontWeight.bold,color: Colors.black),
                              ),
                              onTap: () {
                                print(
                                    userList[findex].document[sindex].title);
                              },
                            );
                          },
                        ),
                      ],
                    );
                  },
                ),
  </code></pre>