postgres function does not handle PUBLIC - expected?

Hello Postgres Gurus,

Is it expected behavior for the has_table_privilege postgres function to not handle the user PUBLIC? Or should I submit a bug?

The has_table_privilege function does not handle PUBLIC – the following queries returns the error:

SELECT has_table_privilege ('PUBLIC','bob.gdb.test1','SELECT') AS SELECT,

has_table_privilege ('PUBLIC','bob.gdb.test1','INSERT') AS INSERT,

has_table_privilege ('PUBLIC','bob.gdb.test1','DELETE') AS DELETE,

has_table_privilege ('PUBLIC','bob.gdb.test1','UPDATE') AS UPDATE;

ERROR:  role "PUBLIC" does not exist

SQL state: 42704

SELECT has_table_privilege ('public','bob.gdb.test1','SELECT') AS SELECT,

has_table_privilege ('public','bob.gdb.test1','INSERT') AS INSERT,

has_table_privilege ('public','bob.gdb.test1','DELETE') AS DELETE,

has_table_privilege ('public','bob.gdb.test1','UPDATE') AS UPDATE;

ERROR: role "public" does not exist

SQL state: 42704

Thank you,

Sincerley,

Kasia