docs: def _filtering_result_checked(self, by_or):
  		'''Check if post passes all / at_least_one (by_or parameter) filter(s).
  			Filters are evaluated on only-if-necessary ("lazy") basis.'''
  		filters, results = it.imap(set, ( self.feed.filters.all(),
  			self.filtering_results.values_list('filter', flat=True) ))
  
  		# Check if conclusion can already be made, based on cached results.
  		if results.issubset(filters):
  			# If at least one failed/passed test is already there, and/or outcome is defined.
  			try: return self._filtering_result(by_or)
  			except IndexError: # inconclusive until results are consistent
  				if filters == results: return not by_or
  
  		# Consistency check / update.
  		if filters != results:
  			# Drop obsolete (removed, unbound from feed)
  			#  filters' results (they WILL corrupt outcome).
  			self.filtering_results.filter(filter__in=results.difference(filters)).delete()
  			# One more try, now that results are only from feed filters' subset.
  			try: return self._filtering_result(by_or)
  			except IndexError: pass
  			# Check if any filter-results are not cached yet, create them (perform actual filtering).
  			# Note that independent filters applied first, since
  			#  crossrefs should be more resource-hungry in general.
  			for filter_obj in sorted(filters.difference(results), key=op.attrgetter('base.crossref')):
  				filter_op = FilterResult(filter=filter_obj, post=self, result=filter_obj.handler(self))
  				filter_op.save()
  				if filter_op.result == by_or: return by_or # return as soon as first passed / failed
  
  		# Final result
  		try: return self._filtering_result(by_or)
  		except IndexError: return not by_or