n operator">: </span><a href="-not-empty-mutable-set/index.html">NotEmptyMutableSet</a><span class="token operator">&lt;</span><span class="token keyword"></span><a href="to-not-empty-mutable-set-or-null.html">E</a><span class="token operator">&gt;</span><span class="token operator">?</span></div><p class="paragraph">Returns a not empty mutable set containing all the elements of this array, or returns <code class="lang-kotlin">null</code> if this array is empty.</p><hr><div class="symbol monospace"><div cla