s OK for a derived method to accept nullable in the params even if the base does not accept nullable.</li></ol><p>NOTE: Rule 1) is based on Java covariance rule for the return type. In contrast, rule 2) is nullsafe specific as Java does not support type contravariance for method params.</p></aside><dl><dt class="spec type" id="type-violation"><a href="#type-violation" class="anchor"></a><code><span class="keyword">type</span> violation</code></dt></dl><div><div class="spec include"><div class="doc"><dl><dt 