evel <span class="token operator">=</span> <span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">incrementProperty</span><span class="token punctuation">(</span><span class="token string">'level'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">if</span> <span class="token punctuation">(</span>newLevel <span class="token operator">===</span> <span class="token number">5</span><span cla