ith a property name to get the value of a property.
 </p>
 <p>
 In a Servlet container, the properties are synchronized with the <code>ServletRequest</code> and expose all the attributes
 available in the <code>ServletRequest</code>. Any modifications of the properties are also reflected in the set of
 properties of the associated <code>ServletRequest</code>.
 </p></div>
<dl class="notes">
<dt>Returns:</dt>
<dd>an immutable <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/Coll