liquibase-core/src/main/java/liquibase/LabelExpression.java
public boolean matches(Labels runtimeLabels) {
        if ((runtimeLabels == null) || runtimeLabels.isEmpty()) {
            return true;
        }
        if (this.labels.isEmpty()) {
            return true;
        }

        for (String expression : this.labels) {
            if (matches(expression, runtimeLabels)) {
                return true;
            }
        }
        return false;
    }
public boolean matches(Labels runtimeLabels) {
        if ((runtimeLabels == null) || runtimeLabels.isEmpty()) {
            return true;
        }
        if (this.labels.isEmpty()) {
            return true;
        }

        for (String expression : this.labels) {
            if (matches(expression, runtimeLabels)) {
                return true;
            }
        }
        return false;
    }
Returns true if the passed runtime labels match this label expression