qm-api-item-header qm-api-item-header-prototype"><span class="qm-api-javascript-header-prototype qm-api-header-details qm-code-font" id="hx.collapseable"><span class="qm-api-javascript-prototype-name">hx.Collapseable</span><span class="qm-api-javascript-prototype-extends">extends</span><span class="qm-api-javascript-prototype-extender"><span class="qm-api-type"><a class="qm-api-type-link" href="/docs/event-emitter/#eventemitter">EventEmitter</a></span></span></span><span class="qm-api-header-tags"></span></