test_sweep01.py includes the following comment during the loop while it waits for sweep to close handles:

# We've configured checkpoints to run every 5 seconds, sweep server to
# run every 2 seconds and idle time to be 6 seconds. It should take
# about 8 seconds for a handle to be closed. Sleep for double to be
# safe. 

The associated code has changed in several ways and the comment should be updated to reflect this:

• The test no longer runs automatic checkpoints
• The sweep server runs every second
• The idle time was reduced to 3 seconds
• The previous two points mean we expect a handle to be closed after 4 seconds
• The code doesn't sleep for double 4 seconds. Instead uses stats to check sweep progress until the expected handles are closed.