Set<Feature<?>> morePresentFeatures = moreRequirements.getPresentFeatures();
    Set<Feature<?>> moreAbsentFeatures = moreRequirements.getAbsentFeatures();
    checkConflict("absent", absentFeatures, "present", morePresentFeatures, source);
    checkConflict("present", presentFeatures, "absent", moreAbsentFeatures, source);
    presentFeatures.addAll(morePresentFeatures);
    absentFeatures.addAll(moreAbsentFeatures);

    Set<Feature<?>> morePresentFeatures = moreRequirements.getPresentFeatures();
    Set<Feature<?>> moreAbsentFeatures = moreRequirements.getAbsentFeatures();
    checkConflict("absent", absentFeatures, "present", morePresentFeatures, source);
    checkConflict("present", presentFeatures, "absent", moreAbsentFeatures, source);
    presentFeatures.addAll(morePresentFeatures);
    absentFeatures.addAll(moreAbsentFeatures);

	// try to see whether existingPorts and wantPorts will conflict or not
	existingPorts := nodeInfo.UsedPorts
	for _, cp := range wantPorts {
		if existingPorts.CheckConflict(cp.HostIP, string(cp.Protocol), cp.HostPort) {
			return false
		}
	}
	return true
}

// New initializes a new plugin and returns it.

func (h HostPortInfo) Len() int {
	length := 0
	for _, m := range h {
		length += len(m)
	}
	return length
}

// CheckConflict checks if the input (ip, protocol, port) conflicts with the existing
// ones in HostPortInfo.
func (h HostPortInfo) CheckConflict(ip, protocol string, port int32) bool {
	if port <= 0 {
		return false
	}

	h.sanitize(&ip, &protocol)

	for _, test := range tests {
		t.Run(test.desc, func(t *testing.T) {
			hp := make(HostPortInfo)
			for _, param := range test.added {
				hp.Add(param.ip, param.protocol, param.port)
			}
			if hp.CheckConflict(test.check.ip, test.check.protocol, test.check.port) != test.expect {
				t.Errorf("expected %t; got %t", test.expect, !test.expect)
			}
		})
	}
}