# Apply skip
	#
	# https://docs.mongodb.com/manual/reference/operator/aggregation/skip/
	#
	# Skips over the specified number of documents that pass into the stage and
	# passes the remaining documents to the next stage in the pipeline.
	#
	# ~~~json
	# { $skip: { <number> } }
	# ~~~
	#
	# If `number == null` then no skip stage is generated
	fun skip(number: nullable Int): MongoPipeline do
		if number == null then return self
		return add_stage("skip", number)
	end