efore be static.

 <p>
 The <code>ExpressionFactory</code> must be able to handle the following types of input for the
 <code>expression</code> parameter:
 <ul>
   <li>Single expressions using the <code>${}</code> delimiter (e.g. <code>"${employee.lastName}"</code>).</li>
   <li>Single expressions using the <code>#{}</code> delimiter (e.g. <code>"#{employee.lastName}"</code>).</li>
   <li>Literal text containing no <code>${}</code> or <code>#{}</code> delimiters (e.g. <code>"John Doe"</code>).</li>
   <li>M