StringUtils.isNumeric is undefined method : <p>I have imported that library:</p>

<pre><code>import org.apache.commons.codec.binary.StringUtils;
</code></pre>

<p>And tried to use some of methods, but failed:</p>

<pre><code>StringUtils.isNumeric("2398sdf");
</code></pre>

<p>IDE keep saying me that, method is undefined. What is wrong here?</p>
