@Override
    public String interpolate(String value) {
        return (String) interpolator.interpolate(value);
    }
Commons-Config interpolation wrapper. This implementation uses a {@link ConfigurationInterpolator} with the default
lookup: <code>sys</code> (system properties), <code>env</code> (environment variables>, and <code>const</code> (constants).

<table>
    <tr>
        <th>lookup</th>
        <th>example</th>
        <th>value</th>
    </tr>
    <tr>
        <td>sys</td>
        <td>${os.name}</td>
        <td>mac os x</td>
    </tr>
    <tr>
        <td>env</td>
        <td>${EDITOR} (resolved from environment variables)</td>
        <td>vi</td>
    </tr>
    <tr>
        <td>const</td>
        <td>${const:java.awt.event.KeyEvent.VK_ENTER}</td>
        <td>\n</td>
    </tr>
</table>

@see ConfigurationInterpolator
@since 1.4
config/ogdl/src/main/java/org/apache/shiro/config/ogdl/CommonsInterpolator.java