presto-base-jdbc/src/main/java/io/prestosql/plugin/jdbc/ForwardingJdbcClient.java/ForwardingJdbcClient/toPrestoType
class ForwardingJdbcClient:    @Override
    public Optional<ColumnMapping> toPrestoType(ConnectorSession session, Connection connection, JdbcTypeHandle typeHandle)
    {
        return getDelegate().toPrestoType(session, connection, typeHandle);
    }