Temporarily disable a role

Hello everyone.

I'm wondering if there is any way we could disable a role temporarily, and
enable it later.

For example, there are two users u1 and u2. User u1 grants the privileges
of its table t1 to role r1:

> grant all on t1 to r1;

Then, role r1 is granted to user u2:

> grant r1 to u2;

Now user u2 should have access to table t1. Here is my question: can we
disable role r1 so that user u2 will not have permissions on table t1? Note
that role r1 is not removed, so we can enable it later.

I expected ALTER ROLE would have some options dealing with this, but could
not find a proper way. Does anyone have ideas? Thanks in advance.

Best regards