)</span></span></div><p class="paragraph">Adds all <a href="plus-assign.html">elements</a> to the end of the <a href="index.html">MutableDoubleList</a>.</p><hr><div class="symbol monospace"><span class="token keyword">inline operator </span><span class="token keyword">fun </span><a href="plus-assign.html"><span class="token function">plusAssign</span></a><span class="token punctuation">(</span><span class="parameters "><span class="parameter ">element<span class="token operator">: </span><a href="https://ko