rules := make(Rules)
	rules.Add(pattern, targetID)

	for _, eventName := range eventNames {
		for _, name := range eventName.Expand() {
			rulesMap[name] = rulesMap[name].Union(rules)
		}
	}
}

// Clone - returns copy of this rules map.
func (rulesMap RulesMap) Clone() RulesMap {
	rulesMapCopy := make(RulesMap)

	for eventName, rules := range rulesMap {