How to check if input string is a hash of algorhitms from list: ["md5", "sha1", "sha256"] : <p>I have to write method like this:</p>

<pre><code>boolean isHash(String str){
  ...
}
</code></pre>

<p>Method should return true if input string is <code>md5</code> hash or <code>sha1</code> hash or <code>sha256</code> hash.</p>

<p>Is it possible to implement such method ?</p>
