Now that __keys are fully hidden, switch the underlying structure to deque() which futher reduces the temptation to index or resort. Also, it is a bit faster for some cases.
Now that __keys are fully hidden, switch the underlying structure
to deque() which futher reduces the temptation to index or resort.
Also, it is a bit faster for some cases.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator