# Returns a new BSON object initialized from the content of `json`.
	#
	# ~~~
	# intrude import mongodb
	# var obj = new JsonObject
	# obj["age"] = 10
	# obj["name"] = "Rick"
	# obj["ELS"] = new JsonArray
	# var bson = new BSON.from_json(obj)
	# assert bson.to_s == """{ "age" : 10, "name" : "Rick", "ELS" : [  ] }"""
	# ~~~
	init from_json(json: JsonObject) do
		init(new NativeBSON.from_json_string(json.to_json.to_cstring))
	end