# Get the item at `key` or return `default` if not in map
	#
	#     var x = new HashMap[String, Int]
	#     x["four"] = 4
	#     assert x.get_or_default("four", 40) == 4
	#     assert x.get_or_default("five", 50) == 50
	#
	fun get_or_default(key: nullable Object, default: V): V
	do
		if has_key(key) then return self[key]
		return default
	end