"target" ValueExpression with the null value.
            </ul>
            <ul>
            If the value of the "value" expression is not null, call getType()
            on the "value" and "target" ValueExpressions to determine their
            property types.
            </ul>
            <ul>
            Coerce the value of the "value" expression to the "target"
            expression value type following the Expression Language coercion
            rules. Call setValue() on the "target" ValueExpressio