targetIDs = targetIDs.Union(targetIDSet)
		}
	}

	return targetIDs
}

// Clone - returns copy of this rules.
func (rules Rules) Clone() Rules {
	rulesCopy := make(Rules)

	for pattern, targetIDSet := range rules {
		rulesCopy[pattern] = targetIDSet.Clone()
	}

	return rulesCopy
}

// Union - returns union with given rules as new rules.

		setCopy[k] = v
	}
	return setCopy
}

// add - adds TargetID to the set.
func (set TargetIDSet) add(targetID TargetID) {
	set[targetID] = struct{}{}
}

// Union - returns union with given set as new set.
func (set TargetIDSet) Union(sset TargetIDSet) TargetIDSet {
	nset := set.Clone()

	for k := range sset {
		nset.add(k)
	}

	return nset
}

		setCopy[k] = v
	}
	return setCopy
}

// add - adds TargetID to the set.
func (set TargetIDSet) add(targetID TargetID) {
	set[targetID] = struct{}{}
}

// Union - returns union with given set as new set.
func (set TargetIDSet) Union(sset TargetIDSet) TargetIDSet {
	nset := set.Clone()

	for k := range sset {
		nset.add(k)
	}

	return nset
}

		{NewTargetIDSet(TargetID{"1", "webhook"}), NewTargetIDSet(TargetID{"1", "webhook"}), NewTargetIDSet(TargetID{"1", "webhook"})},
	}

	for i, testCase := range testCases {
		result := testCase.set.Union(testCase.setToAdd)

		if !reflect.DeepEqual(testCase.expectedResult, result) {
			t.Fatalf("test %v: result: expected: %v, got: %v", i+1, testCase.expectedResult, result)
		}
	}
}