What is the purpose of `this.prototype.constructor = this;`?
<p>In the ASP.NET ajax library, there is a line that makes me confused.</p>

<pre><code>Type.prototype.registerClass = function Type$registerClass(typeName, baseType, interfaceTypes) {

//..

this.prototype.constructor = this;

//..
}
</code></pre>

<p>I know that <code>(this.prototype.constructor === this) == true</code>, so what is significance of this line? I remove the line, and test the library with some code. It seems it is okay. What is the purpose of this line?</p>
