ex.html">infer</a> &#x00BB; <a href="../index.html">Nullsafe</a> &#x00BB; InheritanceRule</nav><h1>Module <code>Nullsafe.InheritanceRule</code></h1></header><aside><p>Inheritance rule:</p><ol><li>Return type for an overridden method is covariant: overridden method is allowed to narrow down the return value to a subtype of the one from the base method; this means it is OK to make the return value non-null when it was nullable in the base)</li><li>Parameter type for an overridden method is contravariant. It i