code: def size(self, value):
  		
  		
  		if self._combining:  # We are a field-compound query fragment, e.g. (Foo.bar & Foo.baz).
  			return reduce(self._combining, (q.size(value) for q in self._field))
  		
  		# Optimize this away in production; diagnosic aide.
  		if __debug__ and _complex_safety_check(self._field, {'$size', '#array'}):  # pragma: no cover
  			raise NotImplementedError("{self!r} does not allow $size comparison.".format(self=self))
  		
  		return Filter({self._name: {'$size': int(value)}})
docs: Selects documents if the array field is a specified size.
  		
  			Document.field.size(5)
  		
  		Array operator: {$size: value}
  		Documentation: https://docs.mongodb.org/manual/reference/operator/query/size/#op._S_size