fails:Enumerable#drop_while returns an Enumerator if no block given
fails:Enumerable#drop_while returns no/all elements for {true/false} block
fails:Enumerable#drop_while accepts returns other than true/false
fails:Enumerable#drop_while passes elements to the block until the first false
fails:Enumerable#drop_while will only go through what's needed
fails:Enumerable#drop_while doesn't return self when it could
fails:Enumerable#drop_while gathers whole arrays as elements when each yields multiple
