@Override
    public int hashCode() {
        int result = name != null ? name.hashCode() : 0;
        result = 31 * result + (param != null ? param.hashCode() : 0);
        return result;
    }
Returns the parameter string for this policy directive.

@return The parameter.
messagebus/src/main/java/com/yahoo/messagebus/routing/PolicyDirective.java