DepSelector uses Ruby's Timeout::timeout, which takes 1 argument `sec` and calls Ruby's `kernel.sleep` under the covers in a separate thread. `kernel.sleep` accepts floats: http://www.ruby-doc.org/core-2.0/Kernel.html#method-i-sleep

Also:

```
irb(main):005:0> Timeout::timeout(3.1) { sleep 3 }
=> 3
irb(main):006:0> Timeout::timeout(3.1) { sleep 3.2 }
Timeout::Error: execution expired
        from (irb):6:in `sleep'
        from (irb):6:in `block in irb_binding'
        from (irb):6
        from /Users/stephen/.rbenv/versions/1.9.3-p194/bin/irb:12:in `<main>'
irb(main):007:0> 
```