Lua-Sqlite3 handler how to wait a few milliseconds?

[albert <albert_200200@...>]

http://www.nessie.de/mroth/lua-sqlite3/documentation.html#ref20
-- Ten attempts are made to proceed, if the database is locked
function my_busy_handler(attempts_made)
  if attempts_made < 10 then
    return true
  else
    return false
  end
end

In the document, it said,"A busy handler could do some other work or 
wait a few milliseconds."
What's the code to wait a few milliseconds? Thanks in advance.