class Rake::Promise

def chore
  if complete?
    stat :found_completed, :item_id => object_id
    return
  end
  stat :will_execute, :item_id => object_id
  begin
    @result = @block.call(*@args)
  rescue Exception => e
    @error = e
  end
  stat :did_execute, :item_id => object_id
  discard
end