presto-main/src/main/java/io/prestosql/sql/planner/LocalDynamicFilter.java/LocalDynamicFilter/addPartition
class LocalDynamicFilter:    private synchronized void addPartition(TupleDomain<String> tupleDomain)
    {
        // Called concurrently by each DynamicFilterSourceOperator instance (when collection is over).
        partitionsLeft -= 1;
        verify(partitionsLeft >= 0);
        // NOTE: may result in a bit more relaxed constraint if there are multiple columns and multiple rows.
        // See the comment at TupleDomain::columnWiseUnion() for more details.
        result = TupleDomain.columnWiseUnion(result, tupleDomain);
        if (partitionsLeft == 0) {
            // No more partitions are left to be processed.
            verify(resultFuture.set(convertTupleDomain(result)), "dynamic filter result is provided more than once");
        }
    }