prelude: |
  def nested_hash h, n
    if n == 0
      ''
    else
      10.times{
        h[Object.new] = nested_hash(h, n-1)
      }
    end
  end

  long_lived = Hash.new
  nested_hash long_lived, 6

  GC.start
  GC.start
benchmark:
  vm_gc_short_with_complex_long: |
    a = '' # short-lived String
    b = ''
    c = ''
    d = ''
    e = ''
    f = ''
loop_count: 30000000