span class="signature">(<wbr><span class="parameter" id="addPlaceholder-param-width"><span class="type-annotation"><a href="../dart-core/double-class.html">double</a></span> <span class="parameter-name">width</span>, </span><wbr><span class="parameter" id="addPlaceholder-param-height"><span class="type-annotation"><a href="../dart-core/double-class.html">double</a></span> <span class="parameter-name">height</span>, </span><wbr><span class="parameter" id="addPlaceholder-param-alignment"><span class="type-ann