 		return nil
 	}
 	
+	/**
+	Extracts the to-many relationship for the given key the passed serialized data.
+	
+	:param: serializedData The data from which to extract the relationship.
+	:param: key            The key for which to extract the relationship from the data.
+	
+	:returns: The extracted relationship or nil if no relationship with the given key was found in the data.
+	*/
 	private func extractToManyRelationship(serializedData: JSONValue, key: String) -> ResourceRelationship? {
 		if let IDs = serializedData["links"][key]["ids"].array {
 			return ResourceRelationship.ToMany(href: serializedData["links"][key]["href"].string!, IDs: IDs.map { return $0.string! }, type: serializedData["links"][key]["type"].string!)

		}
	}
	
	private func extractToOneRelationship(serializedData: JSONValue, key: String) -> ResourceRelationship? {
		if let ID = serializedData["links"][key]["id"].string {
			return ResourceRelationship.ToOne(href: serializedData["links"][key]["href"].string!, ID: ID, type: serializedData["links"][key]["type"].string!)

		}
	}
	
	/**
	 Extracts the value for the given key from the passed serialized data.

	 :param: serializedData The data from which to extract the attribute.
	 :param: key            The key for which to extract the value from the data.

	 :returns: The extracted value or nil if no attribute with the given key was found in the data.
	 */
	private func extractAttribute(serializedData: JSONValue, key: String) -> AnyObject? {
		if let value: AnyObject = serializedData[key].any {
			return value
