s <code>o</code>, <code>o == o</code> must be true.</p></li><li>
<p>Symmetric: For all objects <code>o1</code> and <code>o2</code>, <code>o1 == o2</code> and <code>o2 == o1</code> must
either both be true, or both be false.</p></li><li>
<p>Transitive: For all objects <code>o1</code>, <code>o2</code>, and <code>o3</code>, if <code>o1 == o2</code> and
<code>o2 == o3</code> are true, then <code>o1 == o3</code> must be true.</p></li></ul>
<p>The method should also be consistent over time,
so whether two objects