class="token function"><strike>isNullOrEmpty</strike></span></a><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">: </span><a href="../-op/index.html">Op</a><span class="token operator">&lt;</span><a href="https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-boolean/index.html">Boolean</a><span class="token operator">&gt;</span></div><div class="deprecation-content"><h3 class="">Deprecated (with error)</h3><p class="paragraph">This interface method