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Issue Description
Since query.explain doesn't return a Parse object it causes weird behavior in afterFind.
Steps to reproduce
Create an afterFind trigger, in the afterFind perform some array operation on req.objects. Call query with explain enabled.
Actual Outcome
If the afterFind is empty the explain results are never returned. If afterFind performs some operation they can have unexpected behavior
Expected Outcome
Should skip afterFind or allow explain results to pass through or explain should return array.