filterToString(filter, allLabels, allTiers) {
        const strings = [];
        if (filter.$and) {
            // Not supported
        } else if (filter.$or) {
            for (const subfilter of filter.$or) {
                strings.push(...this.filterToString(subfilter, allLabels, allTiers));
            }
        } else {
            for (const key of Object.keys(filter)) {
                if (key === 'label') {
                    if (typeof filter.label === 'string') {
                        const labelSlug = filter.label;
                        const label = allLabels.find(l => l.get('slug') === labelSlug);
                        if (label) {
                            strings.push(label.get('name'));
                        } else {
                            strings.push(labelSlug);
                        }
                    }
                }
                if (key === 'tier') {
                    if (typeof filter.tier === 'string') {
                        const tierSlug = filter.tier;
                        const tier = allTiers.find(l => l.get('slug') === tierSlug);
                        if (tier) {
                            strings.push(tier.get('name'));
                        } else {
                            strings.push(tierSlug);
                        }
                    }
                }
                if (key === 'status') {
                    if (typeof filter.status === 'string') {
                        if (filter.status === 'free') {
                            strings.push('Free subscribers');
                        } else if (filter.status === 'paid') {
                            strings.push('Paid subscribers');
                        } else if (filter.status === 'comped') {
                            strings.push('Complimentary subscribers');
                        }
                    } else {
                        if (filter.status.$ne === 'free') {
                            strings.push('Paid subscribers');
                        }

                        if (filter.status.$ne === 'paid') {
                            strings.push('Free subscribers');
                        }
                    }
                }
            }
        }

        return strings;
    }
@private Convert an email filter to a human readable string
@param {*} filter Parsed NQL filter
@param {*} allLabels All available member labels
@returns