><span class="token keyword"></span><a href="mutate-values-not-null.html">V</a><span class="token operator">&gt;</span><span class="token punctuation">.</span><a href="mutate-values-not-null.html"><span class="token function">mutateValuesNotNull</span></a><span class="token punctuation">(</span><span class="parameters "><span class="parameter ">transform<span class="token operator">: </span><span class="token punctuation">(</span><span class="token keyword"></span>key<span class="token operator">: </span><a