insert duplicate keys to hash map
<p>I have created hash map and when I debug it I saw that I have duplicte keys.
I didnt override the <code>hashCode()</code> &amp; <code>equals(Object obj)</code> in the key - <code>Object1</code>
and i wonder how will it affect the performance of the map search?</p>

<pre><code>private HashMap&lt;Object1,Object2&gt; map = new HashMap&lt;Object1,Object2&gt;();
</code></pre>
