Extended Groovy Expando class that has equals and hashCode

Expandy.groovy

// Experimental object that could hold general report results.
class Expandy extends Expando {
    boolean equals(Object o) {
        if (getProperties().size() != o.getProperties().size()) return false
        for (def i = getProperties().entrySet().iterator(); i.hasNext(); ) {
            def e = i.next()
            if (!o.getProperties().containsKey(e.getKey())) return false
            def ov = o.getProperty(e.getKey())
            if (ov != e.getValue()) return false
        }
        return true
    }
    int hashCode() {
        int hc = 29
        for (def i = getProperties().entrySet().iterator(); i.hasNext(); ) {
            def e = i.next()
            hc = 13*hc + e.hashCode()
        }
        return hc
    }
}