public Tag getTag() {
        return tag;
    }
A {@link ReplicationFilterPredicate} class to represent the {@link Tag} object
that must exist in the object's tag set in order for the
{@link com.amazonaws.services.s3.model.ReplicationRule} to apply.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/replication/ReplicationTagPredicate.java