text: CREATE FUNCTION
  public.create_language_plpgsql()
  RETURNS BOOLEAN
  STRICT LANGUAGE sql AS $body$
    CREATE LANGUAGE PLPGSQL;
    SELECT TRUE;
  $body$;
  SELECT public.create_language_plpgsql()
    WHERE NOT EXISTS (SELECT TRUE 
                        FROM pg_catalog.pg_language 
                        WHERE lanname = 'plpgsql');
  DROP FUNCTION public.create_language_plpgsql();
  