presto-main/src/main/java/io/prestosql/sql/analyzer/Analysis.java/Analysis/getRelationCoercion
class Analysis:    public Type[] getRelationCoercion(Relation relation)
    {
        return Optional.ofNullable(relationCoercions.get(NodeRef.of(relation)))
                .map(types -> types.stream().toArray(Type[]::new))
                .orElse(null);
    }