parse
DROP USER foo, bar
----
DROP USER foo, bar
DROP USER foo, bar -- fully parenthesized
DROP USER foo, bar -- literals removed
DROP USER _, _ -- identifiers removed

parse
DROP USER IF EXISTS foo, bar
----
DROP USER IF EXISTS foo, bar
DROP USER IF EXISTS foo, bar -- fully parenthesized
DROP USER IF EXISTS foo, bar -- literals removed
DROP USER IF EXISTS _, _ -- identifiers removed

parse
DROP ROLE foo, bar
----
DROP ROLE foo, bar
DROP ROLE foo, bar -- fully parenthesized
DROP ROLE foo, bar -- literals removed
DROP ROLE _, _ -- identifiers removed

parse
DROP ROLE IF EXISTS foo, bar
----
DROP ROLE IF EXISTS foo, bar
DROP ROLE IF EXISTS foo, bar -- fully parenthesized
DROP ROLE IF EXISTS foo, bar -- literals removed
DROP ROLE IF EXISTS _, _ -- identifiers removed
