an class="n">unchanged</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span>
    <span class="n">none</span> <span class="o">=</span> <span class="mi">2</span><span class="p">,</span>        <span class="c1">//!&lt; No ability to read or write anything, but can synchronise (SYNCHRONIZE or 0)
</span><span class="c1"></span>    <span class="n">attr_read</span> <span class="o">=</span> <span class="mi">4</span><span class="p">,</span>   <span class="c1">//!&lt; Ability to read attri