Minor

Author: rubenada

core/src/main/java/org/apache/calcite/rel/rules/LoptOptimizeJoinRule.java

@@ -2090,6 +2090,7 @@ public interface Config extends RelRule.Config {
         .withOperandSupplier(b -> b.operand(MultiJoin.class).anyInputs());
 
     /** Method to calculate intermediate cost computations. */
+    @SuppressWarnings("argument.type.incompatible")
     @Value.Default default BiFunction<RelOptRuleCall, RelNode, RelOptCost> costFunction() {
       return (call, rel) -> call.getMetadataQuery().getCumulativeCost(rel);
     }

core/src/test/java/org/apache/calcite/test/RelOptRulesTest.java

@@ -9749,7 +9749,7 @@ private void checkJoinAssociateRuleWithTopAlwaysTrueCondition(boolean allowAlway
    * <a href="https://issues.apache.org/jira/browse/CALCITE-6788">[CALCITE-6788]
    * LoptOptimizeJoinRule should be able to delegate costs to the planner</a>. */
   @Test void testLoptOptimizeJoinRuleWithSpecialCost() {
-    // Use and ad-hoc version of the rule that uses planner#getCost instead of mq#getCumulativeCost
+    // Use an ad-hoc version of the rule that uses planner#getCost instead of mq#getCumulativeCost
     checkLoptOptimizeJoinRule(LoptOptimizeJoinRule.Config.DEFAULT
         .withCostFunction((c, r) -> c.getPlanner().getCost(r, c.getMetadataQuery()))
         .toRule());